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1999-12-11 03:00:00
2025-04-28 00:58:08
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A380907
Decimal expansion of 1/(2^(1/4)*sqrt(1+Pi/4)).
[ "6", "2", "9", "3", "2", "4", "9", "6", "3", "4", "2", "1", "0", "1", "9", "3", "1", "0", "2", "6", "2", "2", "8", "6", "3", "4", "3", "7", "7", "8", "8", "2", "1", "7", "2", "5", "4", "9", "2", "6", "6", "6", "4", "4", "2", "4", "2", "8", "0", "1", "0", "9", "3", "9", "6", "7", "8", "3", "8", "5", "8", "1", "0", "4", "6", "2", "5", "0", "6", "5", "2", "1", "9", "8", "1", "7", "9", "2", "5", "2", "5", "5", "6", "9", "3", "3", "5", "8", "5", "5", "9", "5", "9", "5", "8", "5", "7", "9", "5", "0" ]
[ "nonn", "cons" ]
7
0
1
[ "A003881", "A010767", "A019704", "A228497", "A380907" ]
null
Stefano Spezia, Feb 08 2025
2025-02-08T09:01:26
oeisdata/seq/A380/A380907.seq
26a637aaa3a1c7eb88fa7767d1dae651
A380908
Decimal expansion of lim_{s->1} (zeta(s) - Pi^(s/2)/((s-1)*Gamma(s/2))) (negated).
[ "9", "7", "6", "9", "0", "4", "2", "9", "1", "0", "3", "3", "8", "7", "8", "9", "6", "6", "1", "8", "5", "6", "8", "9", "7", "5", "2", "0", "9", "3", "5", "0", "4", "7", "0", "8", "3", "7", "8", "0", "6", "7", "8", "7", "2", "8", "4", "7", "9", "4", "9", "2", "4", "0", "4", "7", "4", "6", "0", "7", "9", "2", "7", "7", "8", "7", "0", "2", "8", "6", "4", "3", "5", "2", "3", "2", "7", "5", "4", "2", "0", "0", "2", "9", "2", "0", "1", "4", "3", "0", "4", "8", "8", "2", "9" ]
[ "nonn", "cons" ]
18
0
1
[ "A001620", "A114864", "A155968", "A380908" ]
null
Peter Luschny, Mar 04 2025
2025-03-05T10:42:49
oeisdata/seq/A380/A380908.seq
faa1a8f53d9ccb34c10ab939d711a7c2
A380909
a(n) = numerator(n!! / (n - 1)!!).
[ "1", "1", "2", "3", "8", "15", "16", "35", "128", "315", "256", "693", "1024", "3003", "2048", "6435", "32768", "109395", "65536", "230945", "262144", "969969", "524288", "2028117", "4194304", "16900975", "8388608", "35102025", "33554432", "145422675", "67108864", "300540195", "2147483648", "9917826435", "4294967296", "20419054425" ]
[ "nonn", "frac" ]
27
0
3
[ "A004730", "A004731", "A006882", "A095987", "A380909", "A380910" ]
null
Peter Luschny, Feb 09 2025
2025-02-11T07:13:35
oeisdata/seq/A380/A380909.seq
c2ca6f30571d8236cf547293f028b73d
A380910
a(n) = denominator(n!! / (n - 1)!!).
[ "1", "1", "1", "2", "3", "8", "5", "16", "35", "128", "63", "256", "231", "1024", "429", "2048", "6435", "32768", "12155", "65536", "46189", "262144", "88179", "524288", "676039", "4194304", "1300075", "8388608", "5014575", "33554432", "9694845", "67108864", "300540195", "2147483648", "583401555", "4294967296", "2268783825", "17179869184" ]
[ "nonn", "frac" ]
15
0
4
[ "A004730", "A004731", "A380909", "A380910" ]
null
Peter Luschny, Feb 09 2025
2025-02-11T04:41:29
oeisdata/seq/A380/A380910.seq
c0841aec87f8f958028b12b0d52c0728
A380911
Triangle read by rows: Row n is the initial segment [1, 2, ..., n] sorted into lexicographic order defined by the binary representation of the terms.
[ "1", "1", "2", "1", "2", "3", "1", "2", "4", "3", "1", "2", "4", "5", "3", "1", "2", "4", "5", "3", "6", "1", "2", "4", "5", "3", "6", "7", "1", "2", "4", "8", "5", "3", "6", "7", "1", "2", "4", "8", "9", "5", "3", "6", "7", "1", "2", "4", "8", "9", "5", "10", "3", "6", "7", "1", "2", "4", "8", "9", "5", "10", "11", "3", "6", "7", "1", "2", "4", "8", "9", "5", "10", "11", "3", "6", "12", "7" ]
[ "nonn", "tabl", "base" ]
14
1
3
[ "A007088", "A380911" ]
null
Peter Luschny, Feb 08 2025
2025-02-08T16:06:03
oeisdata/seq/A380/A380911.seq
8a664417e827f20c7152a5a408de3591
A380912
Two-Catalan Triangle read by rows, for n>=0 and k>=0.
[ "1", "1", "1", "1", "3", "6", "6", "3", "1", "15", "36", "40", "29", "15", "5", "1", "91", "232", "280", "238", "154", "76", "28", "7", "1", "603", "1585", "2025", "1890", "1398", "837", "405", "155", "45", "9", "1", "4213", "11298", "15026", "14938", "12078", "8162", "4642", "2211", "869", "274", "66", "11", "1", "30537", "83097", "113841", "118482", "102102", "75075", "47619", "26091", "12285", "4914", "1638", "441", "91", "13", "1" ]
[ "nonn", "tabf" ]
7
0
5
[ "A027907", "A089942", "A380899", "A380912" ]
null
Michel Marcus, Feb 08 2025
2025-02-08T11:11:47
oeisdata/seq/A380/A380912.seq
f158e4f95375c8bb73c28b6d589f123c
A380913
Squarefree semiprimes that are centered triangular numbers.
[ "10", "46", "85", "166", "235", "274", "514", "694", "901", "1135", "1219", "1306", "1585", "1891", "2461", "2839", "3106", "3385", "3826", "3979", "4135", "5311", "5674", "6049", "6835", "7246", "8551", "9481", "10966", "11485", "11749", "12286", "12559", "13969", "15151", "15454", "17335", "18649", "18985", "19666", "21421", "21781", "22879", "23626" ]
[ "nonn" ]
11
1
1
[ "A005448", "A006881", "A184481", "A359624", "A359845", "A380913" ]
null
Massimo Kofler, Feb 08 2025
2025-02-15T23:06:22
oeisdata/seq/A380/A380913.seq
895e514ae1b22120089732c1894752ae
A380914
E.g.f. A(x) satisfies A(x) = exp(x / (1 - x*A(x))) / (1 - x*A(x)).
[ "1", "2", "11", "115", "1797", "37621", "990313", "31452905", "1171010809", "50029903081", "2413119476781", "129719605920565", "7690829719605541", "498579900892422077", "35086898369381747281", "2663953520081549084401", "217057092837921132411249", "18892120969438125131207377", "1749385548844357561820688853" ]
[ "nonn" ]
8
0
2
[ "A380663", "A380769", "A380914", "A380915" ]
null
Seiichi Manyama, Feb 08 2025
2025-02-08T10:30:06
oeisdata/seq/A380/A380914.seq
33682bd3961fb5d02414465fafb31c17
A380915
E.g.f. A(x) satisfies A(x) = exp(x / (1 - x*A(x)^3)) / (1 - x*A(x)^3).
[ "1", "2", "19", "421", "14453", "676741", "40225525", "2901397997", "246222420841", "24038780973913", "2654362957336481", "327087730518759937", "44498835149618922253", "6624743172003104909957", "1071295799491745519081629", "186999332904147675923216341", "35044146207707289182759039825" ]
[ "nonn" ]
9
0
2
[ "A380727", "A380769", "A380914", "A380915" ]
null
Seiichi Manyama, Feb 08 2025
2025-02-08T10:30:02
oeisdata/seq/A380/A380915.seq
7e12b064d60e69c4d3e53a9c8d4ed38e
A380916
E.g.f. A(x) satisfies A(x) = exp(2 * x / (1 - x*A(x))) / (1 - x*A(x)).
[ "1", "3", "20", "254", "4832", "123152", "3947008", "152638320", "6919663360", "359984690432", "21143150157824", "1384004213748224", "99919253031411712", "7887827865170055168", "675952599490594422784", "62495398874421426649088", "6200786173880446466785280", "657212589119205105944428544" ]
[ "nonn" ]
8
0
2
[ "A380914", "A380916", "A380917" ]
null
Seiichi Manyama, Feb 08 2025
2025-02-08T10:29:59
oeisdata/seq/A380/A380916.seq
dd77bc2001bbfd32bee4e5881ee57424
A380917
E.g.f. A(x) satisfies A(x) = exp(3 * x / (1 - x*A(x))) / (1 - x*A(x)).
[ "1", "4", "31", "453", "9957", "293103", "10850625", "484699491", "25381819737", "1525299702363", "103484966417109", "7824985701013143", "652582573442231733", "59509330659228595239", "5890961096785803165129", "629159786981753244521787", "72111288184913038638092337", "8828896697592792281849882547" ]
[ "nonn" ]
7
0
2
[ "A380914", "A380916", "A380917" ]
null
Seiichi Manyama, Feb 08 2025
2025-02-08T10:29:55
oeisdata/seq/A380/A380917.seq
d35a35541c3db7362fba0824f3ba4d7a
A380918
Expansion of e.g.f. (1/x) * Series_Reversion( x * (1 - x) * exp(-2*x/(1 - x)) ).
[ "1", "3", "32", "626", "18144", "701712", "34047712", "1990612752", "136308561408", "10704617527040", "948670854933504", "93670162457937408", "10198210374637791232", "1213835371265476399104", "156812263847161339392000", "21853442119644273456908288", "3268006232205247017382182912", "521999475213929172983534518272" ]
[ "nonn" ]
10
0
2
[ "A380663", "A380916", "A380918", "A380919" ]
null
Seiichi Manyama, Feb 08 2025
2025-02-08T10:29:51
oeisdata/seq/A380/A380918.seq
59f1c281e2b6f409d025acabf86cef41
A380919
Expansion of e.g.f. (1/x) * Series_Reversion( x * (1 - x) * exp(-3*x/(1 - x)) ).
[ "1", "4", "55", "1380", "51213", "2533968", "157230099", "11752365600", "1028673637785", "103250018926080", "11693974366638639", "1475530063767972864", "205281631888995454245", "31221155498006896773120", "5153702313885813394180875", "917695970480270443222536192", "175344823710094148613399084849" ]
[ "nonn" ]
9
0
2
[ "A380663", "A380917", "A380918", "A380919" ]
null
Seiichi Manyama, Feb 08 2025
2025-02-08T10:29:47
oeisdata/seq/A380/A380919.seq
6e526af236aa8081ac753b51154eb6ad
A380920
Triangle read by rows: Define function b(n,k,i) where b(n,k,1) = n/k and b(n,k,i+1) = (i*b(n,k,i))/floor(i*b(n,k,i)). T(n,k) is the smallest number i such that b(n,k,i) = 1.
[ "1", "2", "1", "2", "3", "1", "2", "2", "4", "1", "2", "5", "10", "5", "1", "2", "2", "2", "3", "6", "1", "2", "7", "7", "7", "21", "7", "1", "2", "2", "4", "2", "16", "4", "8", "1", "2", "9", "2", "9", "6", "3", "36", "9", "1", "2", "2", "10", "5", "2", "10", "15", "5", "10", "1", "2", "11", "55", "33", "11", "55", "22", "33", "55", "11", "1", "2", "2", "2", "2", "6", "2", "8", "3", "4", "6", "12", "1", "2", "13" ]
[ "nonn", "tabl" ]
30
1
2
[ "A380920", "A380967" ]
null
Yifan Xie, Feb 08 2025
2025-02-25T11:30:52
oeisdata/seq/A380/A380920.seq
d25a2b39c7ebd0e4a0d662e7999b94dd
A380921
Least k such that A380783(k) = n.
[ "1", "2", "6", "15", "28", "40", "66", "91", "120", "144", "170", "204", "252", "299", "330", "374", "414", "475", "522", "570", "616", "667", "720", "798", "840", "910", "986", "1050", "1116", "1189", "1274", "1333", "1395", "1480", "1554", "1628", "1692", "1776", "1850", "1924", "2016", "2107", "2178", "2244", "2356", "2432", "2511", "2624", "2697", "2808" ]
[ "nonn" ]
5
1
2
[ "A380783", "A380921" ]
null
Pontus von Brömssen, Feb 08 2025
2025-02-08T22:43:50
oeisdata/seq/A380/A380921.seq
c44ca60a23987e0587721b1cdb9e9e0e
A380922
Dirichlet g.f.: zeta(s) * Product_{p prime} (1 + 1/p^s + 1/p^(3*s)).
[ "1", "2", "2", "2", "2", "4", "2", "3", "2", "4", "2", "4", "2", "4", "4", "3", "2", "4", "2", "4", "4", "4", "2", "6", "2", "4", "3", "4", "2", "8", "2", "3", "4", "4", "4", "4", "2", "4", "4", "6", "2", "8", "2", "4", "4", "4", "2", "6", "2", "4", "4", "4", "2", "6", "4", "6", "4", "4", "2", "8", "2", "4", "4", "3", "4", "8", "2", "4", "4", "8", "2", "6", "2", "4", "4", "4", "4", "8", "2", "6", "3", "4", "2", "8", "4", "4", "4", "6", "2", "8", "4", "4", "4", "4", "4", "6", "2", "4", "4", "4" ]
[ "nonn", "mult", "easy", "new" ]
41
1
2
[ "A046100", "A061389", "A073184", "A268335", "A322483", "A336591", "A365498", "A372380", "A380922", "A383292" ]
null
Vaclav Kotesovec, Apr 22 2025
2025-04-22T14:17:51
oeisdata/seq/A380/A380922.seq
823408274ec32a56d3fa488fe9080262
A380923
Integers k such that k = Sum k/(p_i + j), where p_i are the prime factors of k (with multiplicity). Case j = -3.
[ "25", "245", "1250", "2401", "4235", "12250", "41503", "62500", "73205", "120050", "136045", "138985", "211750", "215215", "612500", "717409", "1176490", "1333241", "1362053", "1856465", "2075150", "2109107", "2351635", "2402455", "3125000", "3660250", "3720145", "4561235", "5330605", "5535985", "6002500", "6802250", "6949250" ]
[ "nonn", "easy" ]
4
1
1
[ "A380888", "A380889", "A380900", "A380901", "A380923", "A380924", "A380928" ]
null
Paolo P. Lava, Mar 03 2025
2025-03-03T10:09:14
oeisdata/seq/A380/A380923.seq
abc54e1dcfcee574cf0a36aa2f169c38
A380924
Integers k such that k = Sum k/(p_i + j), where p_i are the prime factors of k (with multiplicity). Case j = 3.
[ "32", "729", "756", "784", "16875", "17500", "18522", "19208", "22950", "23800", "31212", "32368", "37000", "50320", "243760", "390625", "428750", "453789", "470596", "531250", "562275", "570375", "583100", "591500", "722500", "764694", "775710", "793016", "804440", "874125", "906500", "982600", "1188810", "1232840", "1250600" ]
[ "nonn", "easy" ]
3
1
1
[ "A380888", "A380889", "A380900", "A380901", "A380923", "A380924", "A380925", "A380928" ]
null
Paolo P. Lava, Mar 03 2025
2025-03-03T10:09:30
oeisdata/seq/A380/A380924.seq
e5849daaf91d981183b8ea1340bb7308
A380925
Integers k such that k = Sum k/(p_i + j), where p_i are the prime factors of k (with multiplicity). Case j = -4.
[ "5", "75", "100", "343", "1125", "1500", "2000", "5145", "6860", "16875", "22500", "30000", "40000", "77175", "102900", "107653", "137200", "253125", "337500", "352947", "450000", "470596", "600000", "800000", "1157625", "1543500", "1614795", "2058000", "2153060", "2744000", "3796875", "5062500", "5294205", "6750000", "7058940" ]
[ "nonn", "easy" ]
4
1
1
[ "A380888", "A380889", "A380900", "A380901", "A380923", "A380924", "A380925", "A380926", "A380928" ]
null
Paolo P. Lava, Mar 03 2025
2025-03-03T11:13:54
oeisdata/seq/A380/A380925.seq
71556cec3edce604f3b3c0d84ac7fe29
A380926
Integers k such that k = Sum k/(p_i + j), where p_i are the prime factors of k (with multiplicity). Case j = 4.
[ "64", "2000", "2187", "2448", "62500", "76500", "93636", "110484", "159300", "514836", "1953125", "2390625", "2576816", "2926125", "3452625", "3581577", "4009008", "4226013", "4365680", "4615408", "4730352", "4866800", "4978125", "5581488", "6084477", "6093225", "6810608", "6820400", "7396400", "8047600", "8909109", "9456240" ]
[ "nonn", "easy" ]
4
1
1
[ "A380888", "A380889", "A380900", "A380901", "A380923", "A380925", "A380926", "A380927", "A380928" ]
null
Paolo P. Lava, Mar 03 2025
2025-03-03T11:14:10
oeisdata/seq/A380/A380926.seq
8359a69e4a74a61b27fe9795db533765
A380927
Integers k such that k = Sum k/(p_i + j), where p_i are the prime factors of k (with multiplicity). Case j = -5.
[ "49", "1029", "9317", "11858", "15092", "19208", "21609", "195657", "199927", "221221", "244783", "249018", "281554", "311542", "316932", "319319", "396508", "403368", "406406", "453789", "517244", "1771561", "2254714", "2869636", "3652264", "4108797", "4198467", "4645641", "4648336", "5140443", "5229378", "5812079", "5912634" ]
[ "nonn", "easy" ]
3
1
1
[ "A380888", "A380889", "A380900", "A380901", "A380923", "A380926", "A380927", "A380928" ]
null
Paolo P. Lava, Mar 03 2025
2025-03-03T11:14:32
oeisdata/seq/A380/A380927.seq
e1ea5e2f59cf4ab6c7e4889f18a5dc78
A380928
Integers k such that k = Sum k/(p_i + j), where p_i are the prime factors of k (with multiplicity). Case j = 5.
[ "128", "6561", "6624", "250047", "252448", "253125", "264627", "267168", "290871", "293664", "342792", "377622", "381248", "557424", "648432", "762696", "841824", "1109052", "2198208", "2374464", "2472384", "5018304", "9529569", "9646875", "9765625", "10085229", "10209375", "10673289", "10775776", "11085417", "11211291" ]
[ "nonn", "easy" ]
14
1
1
[ "A380888", "A380889", "A380900", "A380901", "A380923", "A380924", "A380925", "A380926", "A380927", "A380928" ]
null
Paolo P. Lava, Mar 04 2025
2025-03-07T10:50:47
oeisdata/seq/A380/A380928.seq
869f2303510e7950cfffa360d6790a2c
A380929
Numbers k such that A380845(k) > 2*k.
[ "36", "72", "84", "140", "144", "168", "180", "264", "270", "280", "288", "300", "336", "360", "372", "392", "450", "520", "528", "532", "540", "558", "560", "576", "594", "600", "612", "620", "672", "720", "744", "756", "780", "784", "840", "900", "930", "1036", "1040", "1050", "1056", "1064", "1068", "1080", "1092", "1116", "1120", "1134", "1152", "1170", "1180", "1188", "1200" ]
[ "nonn", "base", "easy" ]
9
1
1
[ "A000203", "A005101", "A034683", "A064597", "A087248", "A129575", "A129656", "A292982", "A348274", "A348604", "A379029", "A380845", "A380846", "A380847", "A380848", "A380929", "A380930", "A380931" ]
null
Amiram Eldar, Feb 08 2025
2025-02-10T01:40:16
oeisdata/seq/A380/A380929.seq
fc2d4bd28bdb6109cbddb854bd8a6b1e
A380930
Numbers k such that A380845(k) > 3*k.
[ "1080", "2160", "3600", "4320", "7200", "7440", "8640", "11340", "13608", "14400", "14880", "15120", "17280", "18600", "22680", "22860", "27216", "28800", "29760", "30240", "30480", "31752", "33264", "34020", "34560", "37200", "41664", "45360", "45720", "45900", "51408", "53340", "54432", "57600", "59520", "60480", "60960", "61200", "63504" ]
[ "nonn", "base", "easy" ]
8
1
1
[ "A000203", "A068403", "A285615", "A293187", "A300664", "A328135", "A340109", "A380845", "A380846", "A380847", "A380848", "A380929", "A380930", "A380931" ]
null
Amiram Eldar, Feb 08 2025
2025-02-10T01:41:03
oeisdata/seq/A380/A380930.seq
9ec3fed6a45add8da7c074aba909bd71
A380931
Numbers k such that A380845(k) > 4*k.
[ "5155920", "7733880", "10311840", "15467760", "20623680", "30935520", "41247360", "46403280", "61871040", "61901280", "75546240", "82494720", "87693480", "92806560", "103168800", "103194000", "113513400", "123742080", "123802560", "134152200", "140540400", "151092480", "151351200", "162162000", "164989440", "175386960" ]
[ "nonn", "base" ]
8
1
1
[ "A000203", "A068404", "A307114", "A340110", "A380845", "A380846", "A380847", "A380848", "A380929", "A380931" ]
null
Amiram Eldar, Feb 08 2025
2025-02-10T01:41:28
oeisdata/seq/A380/A380931.seq
5b725fae3b849671b41a8dcf8b55c4e6
A380932
Odd numbers k such that A380845(k) > 2*k.
[ "322245", "590205", "874665", "966735", "1934415", "2900205", "3224025", "3378375", "3869775", "4729725", "6081075", "6449625", "6818175", "7740495", "8783775", "8906625", "9029475", "9889425", "10135125", "10961685", "11609325", "11821425", "12900825", "13378365", "14189175", "15049125", "15481935", "15909075", "16253055" ]
[ "nonn", "base" ]
11
1
1
[ "A000203", "A005231", "A005408", "A094889", "A127666", "A129485", "A293186", "A321147", "A339938", "A348275", "A360526", "A379031", "A380845", "A380929", "A380932" ]
null
Amiram Eldar, Feb 08 2025
2025-02-10T01:41:50
oeisdata/seq/A380/A380932.seq
d819ad5c97ddd9db76e9f67534d65242
A380933
Numbers k such that k and k+1 are both in A380929.
[ "121643775", "157390064", "161019495", "275734304", "584899875", "1493214975", "1614323655", "2043708975", "3081783375", "3118599224", "3426851295", "3902652495", "3947893424", "5849043375", "11731509855", "12138531615", "13008843224", "14598032624", "17588484584", "19782621495", "20191564575", "20759209064" ]
[ "nonn", "base" ]
11
1
1
[ "A096399", "A283418", "A318167", "A327635", "A327942", "A331412", "A333951", "A357608", "A364727", "A364861", "A380845", "A380929", "A380932", "A380933" ]
null
Amiram Eldar, Feb 08 2025
2025-02-10T01:40:42
oeisdata/seq/A380/A380933.seq
e6a811f58411d87beabfb14c7a31358f
A380934
Elias delta encoding of n converted from base 2 to integer.
[ "1", "4", "5", "12", "13", "14", "15", "32", "33", "34", "35", "36", "37", "38", "39", "80", "81", "82", "83", "84", "85", "86", "87", "88", "89", "90", "91", "92", "93", "94", "95", "192", "193", "194", "195", "196", "197", "198", "199", "200", "201", "202", "203", "204", "205", "206", "207", "208", "209", "210", "211", "212", "213", "214", "215", "216", "217", "218", "219" ]
[ "nonn", "base", "new" ]
39
1
2
[ "A281150", "A380934" ]
null
Darío Clavijo, Apr 21 2025
2025-04-22T02:34:47
oeisdata/seq/A380/A380934.seq
59e9cf0dedf47a5be077de10354eba3b
A380935
Number of connected cubic identity graphs on 2n vertices.
[ "0", "0", "0", "0", "0", "5", "103", "1547", "22124", "327580", "5181347", "88457008" ]
[ "nonn", "more", "changed" ]
20
1
6
[ "A002851", "A380935", "A380936" ]
null
Eric W. Weisstein, Apr 08 2025
2025-04-14T09:08:07
oeisdata/seq/A380/A380935.seq
3c12b5ce1a4e2a501cb1c7834aa799ec
A380936
Number of connected cubic planar identity graphs on 2n vertices.
[ "0", "0", "0", "0", "0", "2", "18", "154", "1149", "8288", "59682", "433757" ]
[ "nonn", "more", "changed" ]
21
1
6
[ "A380935", "A380936" ]
null
Eric W. Weisstein, Apr 08 2025
2025-04-14T09:08:02
oeisdata/seq/A380/A380936.seq
1b86df3a3f1f0a515e1a602178c8dfbb
A380937
Achilles numbers sandwiched between two semiprimes.
[ "288", "392", "1944", "4500", "4608", "7200", "9248", "13068", "14112", "14792", "16200", "18000", "19652", "21632", "26136", "26912", "28800", "31104", "32000", "34992", "38088", "38988", "41472", "42592", "45000", "48668", "49000", "52272", "55112", "56448", "60552", "69984", "78732", "79092", "87808", "88200", "95832", "98568" ]
[ "nonn", "new" ]
24
1
1
[ "A001358", "A052486", "A380937", "A382831" ]
null
Massimo Kofler, Apr 12 2025
2025-04-18T21:17:11
oeisdata/seq/A380/A380937.seq
2101ff052db151cb68f046e7119d5a34
A380938
Numbers m such that the minimal set of integers to add to the set {A377091(k), k = 0..m} in order to obtain an integer interval contains a positive integer v and its opposite -v.
[ "676", "730", "731", "786", "840", "841", "901", "1060", "1061", "1062", "1063", "1064", "1065", "1066", "1067", "1068", "1069", "1070", "1071", "1072", "1073", "1074", "1075", "1076", "1077", "1078", "1079", "1080", "1081", "1082", "1083", "1084", "1085", "1086", "1087", "1088", "1368", "1369", "1443", "1446", "1447", "1519", "1520", "2115" ]
[ "nonn" ]
7
1
1
[ "A377091", "A380263", "A380501", "A380938", "A380939" ]
null
Rémy Sigrist, Feb 08 2025
2025-02-09T12:18:45
oeisdata/seq/A380/A380938.seq
a443d093245803575ae0f4a4b57fce98
A380939
a(n) is the number of positive integers v that belong alongside their opposites -v to the minimal set of integers to add to the set {A377091(k), k = 0..A380938(n)} in order to obtain an integer interval.
[ "1", "1", "1", "1", "2", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "2", "1", "1", "2", "1", "2", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "2", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1" ]
[ "nonn" ]
6
1
5
[ "A377091", "A380501", "A380938", "A380939" ]
null
Rémy Sigrist, Feb 08 2025
2025-02-09T12:18:55
oeisdata/seq/A380/A380939.seq
60dca4229f5192db0b5b4acaa9899276
A380940
Decimal expansion of the smallest vertex angle, in radians, in a disdyakis triacontahedron face.
[ "5", "7", "1", "9", "4", "9", "2", "5", "6", "1", "1", "9", "3", "8", "6", "8", "5", "5", "9", "8", "4", "1", "5", "4", "6", "2", "7", "1", "5", "5", "3", "3", "8", "2", "4", "1", "5", "0", "7", "3", "0", "4", "0", "5", "4", "6", "7", "3", "1", "0", "2", "8", "4", "8", "6", "4", "8", "0", "5", "2", "5", "5", "1", "4", "4", "3", "6", "4", "2", "2", "1", "3", "0", "7", "6", "9", "6", "6", "1", "0", "6", "7", "3", "0", "2", "8", "3", "6", "1", "9" ]
[ "nonn", "cons", "easy" ]
13
0
1
[ "A001622", "A379388", "A379708", "A379709", "A379710", "A379711", "A380940", "A380941", "A380942" ]
null
Paolo Xausa, Feb 08 2025
2025-02-09T20:11:00
oeisdata/seq/A380/A380940.seq
a1af4aa9b53ca7ddc681965a17dabef6
A380941
Decimal expansion of the middle vertex angle, in radians, in a disdyakis triacontahedron face.
[ "1", "0", "1", "6", "4", "4", "3", "4", "4", "6", "8", "9", "6", "3", "3", "0", "1", "5", "0", "1", "6", "0", "0", "9", "7", "5", "5", "1", "5", "1", "7", "0", "6", "9", "6", "4", "3", "6", "3", "7", "9", "2", "8", "8", "9", "2", "9", "0", "6", "3", "9", "9", "6", "5", "7", "7", "8", "9", "0", "0", "8", "2", "7", "6", "2", "8", "3", "2", "0", "7", "1", "2", "9", "7", "4", "4", "1", "3", "1", "7", "4", "2", "5", "0", "6", "8", "9", "8", "5", "4" ]
[ "nonn", "cons", "easy" ]
9
1
4
[ "A001622", "A379388", "A379708", "A379709", "A379710", "A379711", "A380940", "A380941", "A380942" ]
null
Paolo Xausa, Feb 08 2025
2025-02-09T20:10:38
oeisdata/seq/A380/A380941.seq
3975dad64805612710c98425b2a8d113
A380942
Decimal expansion of the largest vertex angle, in radians, in a disdyakis triacontahedron face.
[ "1", "5", "5", "3", "1", "9", "9", "9", "5", "0", "5", "7", "4", "0", "7", "6", "2", "3", "2", "3", "1", "8", "3", "9", "1", "2", "0", "4", "6", "0", "7", "0", "9", "4", "9", "9", "9", "0", "5", "1", "9", "3", "6", "4", "5", "1", "7", "9", "5", "6", "0", "3", "3", "1", "4", "5", "3", "7", "8", "8", "3", "7", "6", "4", "5", "8", "0", "9", "6", "7", "0", "6", "3", "4", "6", "5", "1", "1", "1", "1", "4", "9", "3", "9", "0", "8", "5", "2", "6", "6" ]
[ "nonn", "cons", "easy" ]
7
1
2
[ "A001622", "A379388", "A379708", "A379709", "A379710", "A379711", "A380940", "A380941", "A380942" ]
null
Paolo Xausa, Feb 09 2025
2025-02-09T20:07:30
oeisdata/seq/A380/A380942.seq
edc537f1b8341e435dcfd6547266a7fd
A380943
Primes written in decimal representation by the concatenation of primes p and q such that the concatenation of q and p also forms a prime.
[ "37", "73", "113", "173", "197", "311", "313", "317", "331", "337", "359", "367", "373", "593", "617", "673", "719", "733", "761", "797", "977", "1093", "1097", "1123", "1277", "1319", "1361", "1373", "1783", "1913", "1931", "1979", "1997", "2293", "2297", "2311", "2347", "2389", "2713", "2837", "2971", "3109", "3119", "3137", "3191", "3229", "3271" ]
[ "nonn", "base" ]
36
1
1
[ "A019549", "A105184", "A133187", "A380943" ]
null
James C. McMahon, Apr 03 2025
2025-04-13T20:00:56
oeisdata/seq/A380/A380943.seq
e907642c44327ffe77d9006b992173ad
A380944
a(n) = b(n,A000120(n)) for n >= 0 where b(n,k) is defined in Comments.
[ "1", "1", "2", "1", "3", "2", "3", "1", "4", "3", "5", "2", "9", "3", "4", "1", "5", "4", "7", "3", "13", "5", "7", "2", "23", "9", "12", "3", "16", "4", "5", "1", "6", "5", "9", "4", "17", "7", "10", "3", "31", "13", "18", "5", "25", "7", "9", "2", "53", "23", "32", "9", "44", "12", "15", "3", "64", "16", "20", "4", "25", "5", "6", "1", "7", "6", "11", "5", "21", "9", "13", "4", "39", "17", "24", "7", "34", "10" ]
[ "nonn", "base" ]
4
0
3
[ "A000120", "A379817", "A379819", "A380944" ]
null
Mikhail Kurkov, Feb 09 2025
2025-02-12T12:57:22
oeisdata/seq/A380/A380944.seq
af59724eff5fa7aa3cb91fab887ae549
A380945
Expansion of e.g.f. (1/x) * Series_Reversion( x * (1 - x)^2 * exp(-2*x) ).
[ "1", "4", "50", "1124", "37192", "1637232", "90278176", "5992556320", "465599728512", "41470892979200", "4167168740195584", "466428111222196224", "57556315795242096640", "7763511917730857967616", "1136484206117494859980800", "179453678311835212416585728", "30404317385796994658988752896" ]
[ "nonn" ]
10
0
2
[ "A370054", "A377832", "A380646", "A380723", "A380945" ]
null
Seiichi Manyama, Feb 09 2025
2025-02-09T09:18:51
oeisdata/seq/A380/A380945.seq
898f7444dddef9dd2f132b17895f074b
A380946
Expansion of e.g.f. (1/x) * Series_Reversion( x * (1 - x)^3 * exp(-3*x) ).
[ "1", "6", "111", "3678", "179073", "11588688", "938905551", "91542271824", "10444685410881", "1365936450693120", "201503447217869679", "33108736185915906816", "5997057218957213126721", "1187319940110958086623232", "255104922613608981003351375", "59120580081196768991316314112" ]
[ "nonn" ]
10
0
2
[ "A370057", "A377833", "A380647", "A380724", "A380946" ]
null
Seiichi Manyama, Feb 09 2025
2025-02-09T09:18:47
oeisdata/seq/A380/A380946.seq
90fb6506ee847eddda67bd93cd070462
A380947
Numerators of rational coefficients which are ratio of Brent's coefficients -A[n,2]/A343480.
[ "0", "0", "1", "1", "3", "7", "5", "5", "23", "39", "63", "17", "209", "185", "1207", "127", "765", "15543", "2499", "1139", "2257", "6327", "309", "21527", "2189", "64273", "6127", "883", "21681", "3835077", "30537", "188579", "7091843", "47895", "8447", "556651", "541", "1978953", "22046359", "1726463", "188751", "45916389", "575107", "2289527", "968180019", "283521", "50207679", "7450167293", "385389", "86547757" ]
[ "nonn", "frac" ]
53
1
5
[ "A307410", "A343480", "A380839", "A380947", "A380948", "A381085" ]
null
Artur Jasinski, Feb 09 2025
2025-03-02T23:38:13
oeisdata/seq/A380/A380947.seq
fa3a236d9b3c0489671c243e80ead71a
A380948
Denominators of rational coefficients which are ratio of Brent's coefficients -A[n,2]/A343480.
[ "1", "1", "1", "1", "2", "2", "2", "2", "4", "8", "16", "2", "40", "32", "80", "20", "112", "1120", "320", "112", "112", "640", "32", "1120", "160", "5600", "280", "64", "1820", "116480", "2240", "14560", "232960", "3136", "364", "18200", "34", "116480", "618800", "76160", "10640", "1074944", "30464", "110656", "18811520", "13600", "2434432", "181060880", "15232", "3043040" ]
[ "nonn", "frac" ]
27
1
5
[ "A307410", "A343480", "A380839", "A380947", "A380948", "A381083" ]
null
Artur Jasinski, Feb 09 2025
2025-03-02T23:38:26
oeisdata/seq/A380/A380948.seq
630571c1afe6d874b59ad6f8e7835b79
A380949
a(n) = numerator(r(n)) where r(n) = (n/2)*(Pi/2)^cos(Pi*(n-1))*((n/2-1/2)!/(n/2)!)^2.
[ "0", "1", "1", "4", "9", "64", "75", "256", "1225", "16384", "19845", "65536", "160083", "1048576", "1288287", "4194304", "41409225", "1073741824", "1329696225", "4294967296", "10667118605", "68719476736", "85530896451", "274877906944", "1371086188563", "17592186044416", "21972535073125", "70368744177664", "176021737014375" ]
[ "nonn", "frac" ]
21
0
4
[ "A001901", "A019267", "A038534", "A056982", "A069955", "A124399", "A161736", "A161737", "A278145", "A380909", "A380910", "A380949", "A380950" ]
null
Peter Luschny, Feb 11 2025
2025-02-14T08:14:16
oeisdata/seq/A380/A380949.seq
13c1c292d744a0df0535e68562da3ddb
A380950
a(n) = denominator(r(n)) where r(n) = (n/2)*(Pi/2)^cos(Pi*(n-1))*((n/2-1/2)!/(n/2)!)^2.
[ "1", "1", "2", "3", "16", "45", "128", "175", "2048", "11025", "32768", "43659", "262144", "693693", "2097152", "2760615", "67108864", "703956825", "2147483648", "2807136475", "17179869184", "44801898141", "137438953472", "178837328943", "2199023255552", "11425718238025", "35184372088832", "45635265151875", "281474976710656" ]
[ "nonn", "frac" ]
15
0
3
[ "A380949", "A380950" ]
null
Peter Luschny, Feb 11 2025
2025-02-14T08:14:32
oeisdata/seq/A380/A380950.seq
f4d616a98aba9c354f078afd2e951b82
A380951
a(n) = 2^(2*n - HammingWeight(n)) * [x^n] ((1 - x)^(-5/2) - (x - 1)^(-2)).
[ "0", "1", "11", "41", "515", "1467", "7847", "20081", "397923", "961255", "4552845", "10609519", "97582823", "221879063", "999384495", "2232200321", "79200753059", "174525593247", "764867505329", "1667683433315", "14479516479981", "31302413221189", "134846186300129", "289480028851479", "4956344862563975", "10577819852813291" ]
[ "nonn" ]
5
0
3
[ "A000120", "A001790", "A046161", "A098597", "A173384", "A380951", "A380952" ]
null
Peter Luschny, Mar 06 2025
2025-03-07T06:40:40
oeisdata/seq/A380/A380951.seq
2e4a541ce2cd79c0e60a00abce52148f
A380952
a(n) = 2^(2*n - HammingWeight(n)) * [x^n] ((x - 1)^(-2) - (1 - x)^(-3/2)).
[ "0", "1", "9", "29", "325", "843", "4165", "9949", "185517", "424415", "1913615", "4263339", "37624977", "82338487", "357893805", "773201629", "26589395581", "56890356903", "242472512971", "514886606335", "4359509125419", "9201491830421", "38741978206771", "81367413504171", "1364185459323625", "2853307081197859" ]
[ "nonn" ]
4
0
3
[ "A000120", "A001790", "A046161", "A098597", "A173384", "A380951", "A380952" ]
null
Peter Luschny, Mar 06 2025
2025-03-07T06:41:07
oeisdata/seq/A380/A380952.seq
1cc99233dddc27fe010d5ef533013dbe
A380953
Numbers m such that the sum of its distinct prime factors and the sum of its nonprime divisors are both squares.
[ "1", "323", "3887", "5183", "149903", "311790", "777923", "1327103", "6718463", "12446783", "14605487", "16402499", "20373435", "28128270", "30856494", "33144430", "37058230", "37380745", "68661901", "86755609", "139557721", "159954570", "221294682", "222538813", "229159043", "269108440", "360590058", "412621345" ]
[ "nonn", "changed" ]
22
1
2
[ "A000203", "A008472", "A164722", "A380953" ]
null
Michel Lagneau, Feb 09 2025
2025-04-26T05:31:17
oeisdata/seq/A380/A380953.seq
91e1c07a8b416f07feda5e4ae4dd7b1e
A380954
E.g.f. A(x) satisfies A(x) = 1/( 1 - x * cosh(x * A(x)^(1/2)) / A(x) ).
[ "1", "1", "0", "3", "12", "5", "240", "1477", "2688", "92241", "708480", "3249191", "99010560", "901895293", "7904053248", "228409722465", "2463665111040", "34395813683297", "972859311194112", "12562427535104683", "244985796671569920", "6929169035680039701", "108002308453438586880", "2673222017277309851453" ]
[ "nonn" ]
25
0
4
[ "A185951", "A380954" ]
null
Seiichi Manyama, Feb 19 2025
2025-02-20T08:39:21
oeisdata/seq/A380/A380954.seq
ccddf9e3e0bddbc23cfaed4ba1e5d523
A380955
Sum of prime indices of n (with multiplicity) minus sum of distinct prime indices of n.
[ "0", "0", "0", "1", "0", "0", "0", "2", "2", "0", "0", "1", "0", "0", "0", "3", "0", "2", "0", "1", "0", "0", "0", "2", "3", "0", "4", "1", "0", "0", "0", "4", "0", "0", "0", "3", "0", "0", "0", "2", "0", "0", "0", "1", "2", "0", "0", "3", "4", "3", "0", "1", "0", "4", "0", "2", "0", "0", "0", "1", "0", "0", "2", "5", "0", "0", "0", "1", "0", "0", "0", "4", "0", "0", "3", "1", "0", "0", "0", "3", "6", "0", "0", "1", "0", "0", "0" ]
[ "nonn" ]
12
1
8
[ "A000040", "A000720", "A001221", "A001222", "A001223", "A005117", "A013929", "A046660", "A055396", "A056239", "A061395", "A066328", "A071625", "A075254", "A075255", "A081770", "A112798", "A116861", "A124010", "A136565", "A178503", "A280286", "A280292", "A290106", "A304038", "A325033", "A325034", "A364916", "A366528", "A366749", "A374248", "A379681", "A380955", "A380956", "A380957", "A380958", "A380986", "A381075" ]
null
Gus Wiseman, Feb 11 2025
2025-02-13T18:29:43
oeisdata/seq/A380/A380955.seq
3582f8d1e010bd123d4ae159ee327bd8
A380956
Position of first appearance of n in A380955 (sum of prime indices minus sum of distinct prime indices).
[ "1", "4", "8", "16", "27", "64", "81", "256", "243", "529", "729", "961", "1369", "1681", "1849", "2209", "2809", "3481", "3721", "4489", "5041", "5329", "6241", "6889", "7921", "9409", "10201", "10609", "11449", "11881", "12769", "16129", "17161", "18769", "19321", "22201", "22801", "24649", "26569", "27889", "29929", "32041", "32761", "36481" ]
[ "nonn" ]
7
0
2
[ "A000040", "A000720", "A001221", "A001222", "A001223", "A005117", "A013929", "A046660", "A055396", "A056239", "A061395", "A066328", "A071625", "A075255", "A112798", "A116861", "A136565", "A151821", "A156061", "A175508", "A178503", "A280286", "A280292", "A290106", "A304038", "A325033", "A364916", "A366528", "A366749", "A374248", "A380955", "A380956", "A380957", "A380958", "A380986", "A380987", "A380988", "A380989", "A381075" ]
null
Gus Wiseman, Feb 12 2025
2025-02-13T18:29:33
oeisdata/seq/A380/A380956.seq
eab11a57a6eac6d05a220898f5dd70b6
A380957
Sorted positions of first appearances in A380955 (sum of prime indices minus sum of distinct prime indices).
[ "1", "4", "8", "16", "27", "64", "81", "243", "256", "529", "729", "961", "1369", "1681", "1849", "2209", "2809", "3481", "3721", "4489", "5041", "5329", "6241", "6889", "7921", "9409", "10201", "10609", "11449", "11881", "12769", "16129", "17161", "18769", "19321", "22201", "22801", "24649", "26569", "27889", "29929", "32041", "32761", "36481" ]
[ "nonn" ]
6
1
2
[ "A000040", "A000720", "A001222", "A001223", "A005117", "A013929", "A046660", "A055396", "A056239", "A061395", "A071625", "A075255", "A112798", "A116861", "A136565", "A151821", "A156061", "A175508", "A178503", "A280286", "A280292", "A290106", "A325033", "A364916", "A366528", "A366749", "A374248", "A380955", "A380956", "A380957", "A380958", "A380986", "A380987", "A380988", "A380989", "A381075" ]
null
Gus Wiseman, Feb 13 2025
2025-02-16T13:36:29
oeisdata/seq/A380/A380957.seq
45ac643735df421c3c6b9d45185184fb
A380958
Number of prime factors of n (with multiplicity) minus sum of distinct prime exponents of n.
[ "0", "0", "0", "0", "0", "1", "0", "0", "0", "1", "0", "0", "0", "1", "1", "0", "0", "0", "0", "0", "1", "1", "0", "0", "0", "1", "0", "0", "0", "2", "0", "0", "1", "1", "1", "2", "0", "1", "1", "0", "0", "2", "0", "0", "0", "1", "0", "0", "0", "0", "1", "0", "0", "0", "1", "0", "1", "1", "0", "1", "0", "1", "0", "0", "1", "2", "0", "0", "1", "2", "0", "0", "0", "1", "0", "0", "1", "2", "0", "0", "0", "1", "0", "1", "1", "1", "1" ]
[ "nonn" ]
8
1
30
[ "A000040", "A000720", "A001221", "A001222", "A001223", "A005117", "A005361", "A013929", "A046660", "A051903", "A051904", "A055396", "A056239", "A061395", "A071625", "A075254", "A075255", "A076694", "A081770", "A112798", "A116861", "A124010", "A130091", "A130092", "A136565", "A178503", "A280286", "A280292", "A290106", "A296150", "A380955", "A380956", "A380957", "A380958", "A380986", "A380989", "A381075" ]
null
Gus Wiseman, Feb 13 2025
2025-02-16T13:36:20
oeisdata/seq/A380/A380958.seq
0b3890a6b2c0365596e6427dd43652f2
A380959
Array read by antidiagonals downward where A(n,k) is the number of integer partitions of k with product n.
[ "1", "1", "0", "1", "0", "0", "1", "1", "0", "0", "1", "1", "0", "0", "0", "1", "1", "1", "0", "0", "0", "1", "1", "1", "0", "0", "0", "0", "1", "1", "1", "2", "0", "0", "0", "0", "1", "1", "1", "2", "0", "0", "0", "0", "0", "1", "1", "1", "2", "1", "0", "0", "0", "0", "0", "1", "1", "1", "2", "1", "1", "0", "0", "0", "0", "0", "1", "1", "1", "2", "1", "2", "0", "0", "0", "0", "0", "0" ]
[ "nonn", "tabl" ]
11
0
32
[ "A000009", "A000041", "A001055", "A002865", "A003963", "A008284", "A025147", "A028422", "A045778", "A057567", "A057568", "A069016", "A096276", "A111133", "A114324", "A301987", "A316439", "A318029", "A318950", "A319000", "A319005", "A319057", "A319916", "A325036", "A325037", "A325038", "A325041", "A325042", "A325044", "A326149", "A326152", "A326155", "A326622", "A328966", "A379666", "A379667", "A379668", "A379669", "A379670", "A379671", "A379672", "A379678", "A379721", "A379722", "A379733", "A379736", "A380959" ]
null
Gus Wiseman, Feb 10 2025
2025-02-11T00:00:02
oeisdata/seq/A380/A380959.seq
1ffef610afda80b034744cc3270fe3e2
A380960
Sum of n and the n-th bit of the infinite Fibonacci word.
[ "0", "2", "2", "3", "5", "5", "7", "7", "8", "10", "10", "11", "13", "13", "15", "15", "16", "18", "18", "20", "20", "21", "23", "23", "24", "26", "26", "28", "28", "29", "31", "31", "32", "34", "34", "36", "36", "37", "39", "39", "41", "41", "42", "44", "44", "45", "47", "47", "49", "49", "50", "52", "52", "54", "54", "55", "57", "57", "58", "60", "60", "62", "62", "63", "65", "65", "66" ]
[ "nonn" ]
7
0
2
[ "A003849", "A368050", "A380960" ]
null
Jeffrey Shallit, Feb 09 2025
2025-02-09T12:29:24
oeisdata/seq/A380/A380960.seq
9fa5c4233b8eb56ee17a2b8efe7a6a7c
A380961
Primes prime(k) such that (prime(k) + prime(k+1)) mod (prime(k) - prime(k-1)) != 0.
[ "53", "97", "127", "157", "173", "191", "211", "223", "251", "257", "263", "307", "331", "347", "367", "373", "397", "401", "409", "431", "457", "467", "479", "487", "491", "499", "509", "541", "563", "593", "607", "641", "653", "673", "709", "719", "727", "733", "743", "751", "761", "769", "787", "797", "821", "839", "853", "877", "887", "907", "911", "929", "937", "947", "967", "977", "991", "997", "1009", "1031", "1061", "1069", "1103", "1123" ]
[ "nonn", "easy" ]
26
1
1
[ "A000040", "A001043", "A001223", "A380961" ]
null
Najeem Ziauddin, Feb 09 2025
2025-02-24T08:53:04
oeisdata/seq/A380/A380961.seq
795db19312a21ea1ceb9f9315ccbdafb
A380962
Number of ways to place eight distinct positive integers on a square, four on the corners and four on the sides such that the sum of the three values on each side is n.
[ "3", "9", "23", "48", "84", "132", "226", "304", "456", "629", "849", "1079", "1501", "1794", "2317", "2898", "3519", "4195", "5288", "6049", "7282", "8605", "10017", "11494", "13662", "15273", "17680", "20231", "22842", "25573", "29432", "32353", "36463", "40791", "45216", "49803", "55926", "60759", "67295", "74071", "80929", "88034", "97283", "104713", "114359", "124383", "134526", "144957", "158110" ]
[ "nonn", "easy" ]
20
12
1
[ "A005994", "A006325", "A380853", "A380962" ]
null
Derek Holton and Alex Holton, Feb 09 2025
2025-03-19T05:55:48
oeisdata/seq/A380/A380962.seq
350a107c88d76e3daafb42b21868cd34
A380963
The number of perimeter-magic pentagons of order 3 with magic sum n.
[ "1", "9", "33", "75", "233", "374", "742", "1294", "2042", "3029", "4931", "6535", "9507", "13214", "17577", "22762", "31335", "38341", "49660", "62791", "77689", "94239", "119151", "139727", "170553", "204832", "242122", "282811", "340914", "388834", "456668", "530819", "609982", "694982", "810204", "906951", "1038672" ]
[ "nonn" ]
13
14
2
[ "A380853", "A380962", "A380963", "A380964" ]
null
Derek Holton and Alex Holton, Feb 09 2025
2025-03-19T05:54:37
oeisdata/seq/A380/A380963.seq
859319f158169f318816c0ed5b343386
A380964
Perimeter-magic hexagons of order 3 with magic sum n.
[ "9", "48", "150", "494", "1202", "2542", "4635", "9738", "14943", "25917", "41196", "62518", "89657", "139743", "185114", "264483", "363291", "485411", "630099", "862106", "1067459", "1391011", "1771817", "2210554", "2712337", "3461467", "4115434", "5073010", "6165577", "7387876", "8748214", "10655591", "12333486", "14679050", "17281206" ]
[ "nonn" ]
16
17
1
[ "A380853", "A380962", "A380963", "A380964" ]
null
Derek Holton and Alex Holton, Feb 09 2025
2025-03-15T17:10:32
oeisdata/seq/A380/A380964.seq
1f970da46343683191c5a0996f11b4aa
A380965
Decimal expansion of the solution to e^(x+Pi) = Pi^(x+e).
[ "2", "0", "6", "5", "5", "1", "7", "1", "6", "7", "7", "8", "6", "4", "9", "6", "6", "3", "9", "1", "3", "0", "7", "1", "7", "5", "6", "3", "0", "8", "6", "9", "6", "9", "8", "5", "0", "2", "3", "0", "9", "1", "4", "4", "3", "9", "0", "2", "7", "8", "7", "2", "4", "7", "5", "8", "1", "2", "9", "1", "8", "5", "7", "2", "0", "4", "2", "4", "6", "3", "1", "4", "6", "8", "6", "6", "1", "0", "5", "7", "1", "3", "1", "3", "6", "5", "4", "7", "5", "7", "2", "6", "4", "4", "0", "9", "8", "6", "6", "5" ]
[ "nonn", "cons" ]
29
0
1
[ "A000796", "A001113", "A039661", "A053510", "A059850", "A179701", "A380965" ]
null
Stefano Spezia, Feb 09 2025
2025-02-11T02:59:14
oeisdata/seq/A380/A380965.seq
01c236831afc49d4ba1ac137909b594f
A380966
a(n) is an upper bound such that there exists an m X m magic square of n-th powers for all m >= a(n).
[ "36", "52", "84", "140", "164", "196", "224", "252", "284", "312", "344", "372", "404", "436", "468", "500", "532", "564", "596", "632", "664", "696", "732", "764", "796", "832", "864", "900", "936", "968", "1004", "1036", "1072", "1108", "1144", "1180", "1212", "1248", "1284", "1320", "1356", "1392", "1428", "1464", "1500", "1536", "1572", "1608", "1644", "1680" ]
[ "nonn" ]
7
2
1
[ "A364264", "A380966" ]
null
Paolo Xausa, Feb 09 2025
2025-02-10T20:47:24
oeisdata/seq/A380/A380966.seq
8042ec15e10e8da6af64d4dcd2c71e7e
A380967
a(n) is the largest number in row n of A380920.
[ "1", "2", "3", "4", "10", "6", "21", "16", "36", "15", "55", "12", "2080", "56", "105", "64", "1496", "36", "209", "120", "210", "1276", "897", "96", "375", "2080", "351", "210", "42688", "120", "11935", "5376", "2376", "32385", "7525", "351", "11137", "4465", "2080", "260", "621396", "378", "266815", "13728", "81810", "21321", "186355", "5376", "634501" ]
[ "nonn" ]
22
1
2
[ "A380920", "A380967" ]
null
Yifan Xie, Feb 09 2025
2025-02-26T08:53:10
oeisdata/seq/A380/A380967.seq
fdcdfe8a06beec1c5304fee3b4d052c7
A380968
Lexicographically earliest sequence of positive integers such that for any value k, no two sets of one or more indices at which k occurs have the same mean.
[ "1", "1", "2", "1", "2", "2", "3", "1", "3", "3", "2", "4", "4", "5", "3", "1", "4", "5", "5", "6", "6", "7", "4", "6", "7", "2", "5", "8", "6", "3", "7", "1", "7", "5", "8", "8", "4", "9", "8", "9", "9", "10", "10", "6", "10", "9", "11", "11", "10", "11", "2", "8", "12", "11", "3", "7", "10", "12", "5", "12", "9", "11", "4", "13", "13", "14", "13", "12", "6", "14", "13", "14", "10", "15", "15", "16", "15", "11", "13" ]
[ "nonn" ]
14
1
3
[ "A380751", "A380783", "A380968" ]
null
Neal Gersh Tolunsky, Feb 09 2025
2025-02-12T21:40:24
oeisdata/seq/A380/A380968.seq
339d94610b0133b33046d843b47980f4
A380969
a(n) is the smallest k such that tau(k^2 + 1) is equal to 2^n, where tau = A000005 and a(n) = -1 if no such k exists.
[ "0", "1", "3", "13", "47", "307", "2163", "17557", "191807", "1413443", "16485763", "169053487" ]
[ "nonn", "hard", "more" ]
18
0
3
[ "A000005", "A164511", "A180278", "A353008", "A380798", "A380969" ]
null
Juri-Stepan Gerasimov, Feb 09 2025
2025-02-18T17:39:26
oeisdata/seq/A380/A380969.seq
ed3b95fb0123e4200dc5829a92609e56
A380970
a(n) = Sum_{k=1..p-1} floor(k^p/p) where p is prime(n).
[ "0", "2", "258", "53820", "12942210870", "11901444483390", "25627001801054931000", "55413915436873048932450", "490667517005738962388828685972", "48588952813858892791005036793649985985110", "303307728036900627681487165427498812641117360", "158544898951978777519612048992784361843596346824881328530" ]
[ "nonn" ]
5
1
2
[ "A078837", "A361559", "A380970" ]
null
Michel Marcus, Feb 09 2025
2025-02-10T04:41:12
oeisdata/seq/A380/A380970.seq
a59be757364a145219c3592d7cd30ec5
A380971
Irregular triangle T(n, k), n >= 0, k > 0, read by rows with row polynomials R(n, x) such that R(2n+1, x) = x*R(n, x) for n >= 0, R(2n,x) = wt(n)*x*((x+1)^wt(n) - x^wt(n)) + Sum_{k=1..wt(n)} k*x^k*T(n,k) for n > 0 with R(0,x) = 0 where wt(n) = A000120(n).
[ "1", "2", "0", "1", "2", "4", "3", "0", "2", "2", "6", "0", "0", "1", "4", "12", "0", "2", "4", "3", "9", "9", "4", "0", "3", "2", "8", "0", "0", "2", "4", "16", "0", "2", "6", "3", "9", "12", "0", "0", "0", "1", "6", "28", "0", "4", "12", "3", "13", "21", "0", "0", "2", "4", "6", "27", "36", "0", "3", "9", "9", "4", "16", "24", "16", "5", "0", "4", "2", "10", "0", "0", "3", "4", "20", "0", "2", "8", "3", "9", "15", "0" ]
[ "nonn", "base", "tabf" ]
5
0
2
[ "A000120", "A373183", "A380179", "A380944", "A380971" ]
null
Mikhail Kurkov, Feb 10 2025
2025-02-12T12:59:14
oeisdata/seq/A380/A380971.seq
7cc64e69a16d35835413d6550e1fffba
A380972
Expansion of e.g.f. (1/x) * Series_Reversion( x * exp(-x*exp(2*x)) ).
[ "1", "1", "7", "76", "1237", "26816", "728899", "23866816", "915129961", "40237778944", "1996402790431", "110351882157056", "6725593733125117", "448106469169905664", "32404532970216803803", "2527793703574203252736", "211589448225820679029969", "18917558526854862344290304", "1799285901282568752019291063" ]
[ "nonn" ]
9
0
3
[ "A162695", "A380879", "A380972", "A380973" ]
null
Seiichi Manyama, Feb 10 2025
2025-02-10T04:42:44
oeisdata/seq/A380/A380972.seq
cbbf5c1f44f5e1879103f87bc6039f4b
A380973
Expansion of e.g.f. (1/x) * Series_Reversion( x * exp(-x*exp(3*x)) ).
[ "1", "1", "9", "115", "2213", "56781", "1825735", "70718383", "3207565737", "166830072409", "9791107408331", "640182529765395", "46152280917472669", "3637314366894167077", "311129703773921407887", "28708644100373375591191", "2842495895373573092038865", "300611288206029730901431473", "33820062046972635799385887123" ]
[ "nonn" ]
10
0
3
[ "A162695", "A380880", "A380972", "A380973" ]
null
Seiichi Manyama, Feb 10 2025
2025-02-10T04:42:30
oeisdata/seq/A380/A380973.seq
a7ef94b06076406b1cb0ceecc20ad3e6
A380974
Numbers k such that k*(k-1) is composed of exactly two different decimal digits.
[ "4", "5", "6", "7", "8", "9", "10", "11", "17", "24", "25", "32", "34", "67", "75", "78", "100", "101", "142", "167", "334", "667", "1000", "1001", "1667", "3334", "6667", "10000", "10001", "16667", "33334", "66667", "100000", "100001", "166667", "333334", "666667", "1000000", "1000001", "1666667", "3333334", "6666667", "10000000", "10000001", "16666667", "33333334", "66666667", "100000000" ]
[ "nonn", "base" ]
44
1
1
[ "A002378", "A016069", "A031955", "A380974", "A380984" ]
null
Robert Israel, Feb 11 2025
2025-02-21T13:07:40
oeisdata/seq/A380/A380974.seq
a66b3d985493fd051fdbbca3980306c8
A380975
Self-convolution of A300116.
[ "1", "80", "5616", "378880", "25108976", "1647924480", "107513168896", "6986714808320", "452774526525936", "29282607270465280", "1890903981075228416", "121957594044379545600", "7858392761937306551296", "505967049989822738186240", "32556176323125901615005696", "2093691733876474661699584000" ]
[ "nonn" ]
3
0
2
[ "A300116", "A380975" ]
null
Vaclav Kotesovec, Feb 10 2025, following a suggestion from John M. Campbell
2025-02-10T06:28:23
oeisdata/seq/A380/A380975.seq
a7badaadc0f5cc37f3eed176261d015a
A380976
a(0) = 0, a(1) = 1. Thereafter, a(n) = a(n-1) + a(n-2) converted to base n, read in base n+1.
[ "0", "1", "1", "2", "3", "6", "10", "18", "31", "54", "93", "172", "300", "536", "955", "1686", "2976", "5224", "9491", "17089", "30618", "54774", "97553", "172749", "305164", "554749", "982005", "1757750", "3140769", "5584153", "9924579", "17582197", "31100841", "56191241", "99509416", "177595495", "316647651", "564436376", "1002970166" ]
[ "nonn", "base" ]
42
0
4
null
null
Kaleb Williams, Feb 10 2025
2025-02-15T02:13:10
oeisdata/seq/A380/A380976.seq
feb23c8c463f96b482a4e3d66786f736
A380977
Triangle read by rows: T(n,m) (1<=m<=n.) = number of surjections f:[n]->[m] with f(n)!=f(j), j<n;
[ "1", "0", "2", "0", "2", "6", "0", "2", "18", "24", "0", "2", "42", "144", "120", "0", "2", "90", "600", "1200", "720", "0", "2", "186", "2160", "7800", "10800", "5040", "0", "2", "378", "7224", "42000", "100800", "105840", "40320", "0", "2", "762", "23184", "204120", "756000", "1340640", "1128960", "362880", "0", "2", "1530", "72600", "932400", "5004720", "13335840", "18627840", "13063680", "3628800" ]
[ "nonn", "tabl" ]
10
1
3
[ "A005649", "A048993", "A068293", "A131689", "A380977" ]
null
Manfred Boergens, Feb 10 2025
2025-02-21T13:50:50
oeisdata/seq/A380/A380977.seq
32162aa269d5912b707fecff93e356ce
A380978
Sequence of minimal Fermat witnesses for compositeness. a(n) is the least k such that the smallest composite number that is a Fermat pseudoprime to bases {a(i) : 1 <= i < n} is not a Fermat pseudoprime to base k.
[ "2", "3", "5", "7", "13", "11", "17", "41", "37", "19", "31", "43", "23", "53", "29", "101", "61", "109", "71", "67", "73", "113", "151", "89", "97", "211", "191", "157", "163", "193", "139", "281", "107", "103", "181", "47", "127", "271", "131", "307", "59", "257", "229", "331", "337", "199", "241", "461", "239", "617", "367", "263", "401", "251", "149", "421", "137", "277" ]
[ "nonn" ]
25
1
1
[ "A001567", "A089105", "A321790", "A380978", "A380979" ]
null
Jan Kostanjevec, Feb 10 2025
2025-03-18T22:21:44
oeisdata/seq/A380/A380978.seq
e39a0f8bbebf2eb371b1362118be665d
A380979
Composites that cause a witness to be added to a set of Fermat witnesses: a(n) is the smallest composite number that is not guaranteed composite using Fermat's Little Theorem by the witness A380978(i) for any i < n.
[ "4", "341", "1105", "1729", "29341", "75361", "162401", "252601", "294409", "334153", "399001", "1152271", "1615681", "2508013", "3581761", "3828001", "6189121", "6733693", "10024561", "10267951", "14469841", "17098369", "17236801", "19384289", "23382529", "29111881", "34657141", "53711113", "64377991", "79411201", "79624621" ]
[ "nonn" ]
29
1
1
[ "A001567", "A002997", "A006945", "A098654", "A135720", "A380978", "A380979" ]
null
Jan Kostanjevec, Feb 10 2025
2025-03-18T22:21:57
oeisdata/seq/A380/A380979.seq
e6604f4bb44b067ffa52ff70d509a380
A380980
Place 2n distinct positive integers on an n-gon, n on the vertices and n on the sides such that the sums of the three values on all sides are equal. a(n) is the minimal sum of all the integers used.
[ "21", "38", "55", "81", "105", "140" ]
[ "nonn", "more" ]
15
3
1
[ "A380853", "A380980" ]
null
Ivan N. Ianakiev, Feb 10 2025
2025-02-13T08:26:28
oeisdata/seq/A380/A380980.seq
88530f37dfb0c57a2f1586d4a234153f
A380981
Decimal expansion of the medium/short edge length ratio of a disdyakis triacontahedron.
[ "1", "5", "7", "0", "8", "2", "0", "3", "9", "3", "2", "4", "9", "9", "3", "6", "9", "0", "8", "9", "2", "2", "7", "5", "2", "1", "0", "0", "6", "1", "9", "3", "8", "2", "8", "7", "0", "6", "3", "2", "1", "8", "5", "5", "0", "7", "8", "8", "3", "4", "5", "7", "7", "1", "7", "2", "8", "1", "2", "6", "9", "1", "7", "3", "6", "2", "3", "1", "5", "6", "2", "7", "7", "6", "9", "1", "3", "4", "1", "4", "6", "9", "8", "2", "4", "3", "2", "4", "3", "2" ]
[ "nonn", "cons", "easy" ]
10
1
2
[ "A002163", "A010499", "A134976", "A176015", "A379388", "A379708", "A379709", "A379710", "A379711", "A380940", "A380941", "A380942", "A380981", "A380982" ]
null
Paolo Xausa, Feb 10 2025
2025-02-13T21:15:42
oeisdata/seq/A380/A380981.seq
6ada8bd7f220d592cb76fb1de7053a7d
A380982
Decimal expansion of the long/short edge length ratio of a disdyakis triacontahedron.
[ "1", "8", "4", "7", "2", "1", "3", "5", "9", "5", "4", "9", "9", "9", "5", "7", "9", "3", "9", "2", "8", "1", "8", "3", "4", "7", "3", "3", "7", "4", "6", "2", "5", "5", "2", "4", "7", "0", "8", "8", "1", "2", "3", "6", "7", "1", "9", "2", "2", "3", "0", "5", "1", "4", "4", "8", "5", "4", "1", "7", "9", "4", "4", "9", "0", "8", "2", "1", "0", "4", "1", "8", "5", "1", "2", "7", "5", "6", "0", "9", "7", "9", "8", "8", "2", "8", "8", "2", "8", "8" ]
[ "nonn", "cons", "easy" ]
10
1
2
[ "A010476", "A020762", "A134974", "A176453", "A379388", "A379708", "A379709", "A379710", "A379711", "A380940", "A380941", "A380942", "A380981", "A380982" ]
null
Paolo Xausa, Feb 10 2025
2025-02-13T21:15:47
oeisdata/seq/A380/A380982.seq
d4a107913aefa904dbb98b9b7ecb1a37
A380983
Numbers m whose sum of unitary divisors different from 1 and m is prime.
[ "6", "10", "12", "18", "22", "24", "28", "30", "34", "36", "40", "42", "48", "52", "54", "58", "60", "70", "72", "76", "78", "82", "88", "90", "100", "102", "108", "112", "118", "126", "132", "138", "142", "148", "160", "162", "172", "184", "186", "192", "196", "202", "208", "214", "220", "222", "232", "238", "240", "246", "250", "258", "264", "268", "270", "274", "280" ]
[ "nonn" ]
9
1
1
[ "A034448", "A380983" ]
null
Michel Lagneau, Feb 11 2025
2025-02-26T11:25:17
oeisdata/seq/A380/A380983.seq
60516c1e7f6ca9b574a532c5d80fba39
A380984
Primes p such that p*(p-1) consists of exactly two different decimal digits.
[ "5", "7", "11", "17", "67", "101", "167", "1667", "166667", "666667", "66666667", "666666667", "1666666667", "66666666667", "166666666667", "166666666666667", "66666666666666666667" ]
[ "nonn", "base", "more" ]
23
1
1
[ "A076850", "A096507", "A380974", "A380984" ]
null
Robert Israel, Feb 11 2025
2025-02-20T06:32:38
oeisdata/seq/A380/A380984.seq
08b575194b15d895c2232bf82dbf6311
A380985
Numbers whose k-th digit indicates the number of digits which occur k times.
[ "1", "20", "110", "2100", "20100", "200100", "2000100", "20000100", "200000100", "2000000100", "20000000100", "200000000100", "2000000000100", "20000000000100", "200000000000100", "2000000000000100", "20000000000000100", "200000000000000100", "2000000000000000100", "20000000000000000100" ]
[ "nonn", "easy", "base" ]
25
1
2
[ "A046043", "A380985" ]
null
Leo Crabbe, Feb 11 2025
2025-02-23T13:43:44
oeisdata/seq/A380/A380985.seq
048e3ea3bc5ee69aacc2de495cf7cb92
A380986
Product of prime indices of n (with multiplicity) minus product of distinct prime indices of n.
[ "0", "0", "0", "0", "0", "0", "0", "0", "2", "0", "0", "0", "0", "0", "0", "0", "0", "2", "0", "0", "0", "0", "0", "0", "6", "0", "6", "0", "0", "0", "0", "0", "0", "0", "0", "2", "0", "0", "0", "0", "0", "0", "0", "0", "6", "0", "0", "0", "12", "6", "0", "0", "0", "6", "0", "0", "0", "0", "0", "0", "0", "0", "8", "0", "0", "0", "0", "0", "0", "0", "0", "2", "0", "0", "12", "0", "0", "0", "0", "0", "14", "0", "0", "0", "0", "0" ]
[ "nonn" ]
7
1
9
[ "A000040", "A000720", "A001221", "A001222", "A001223", "A003557", "A003963", "A005117", "A007947", "A013929", "A038838", "A046660", "A055396", "A056239", "A061395", "A066328", "A066503", "A075255", "A081770", "A112798", "A116861", "A156061", "A178503", "A280286", "A280292", "A290106", "A304038", "A374248", "A379681", "A380955", "A380956", "A380957", "A380958", "A380986", "A381075" ]
null
Gus Wiseman, Feb 14 2025
2025-02-18T15:34:33
oeisdata/seq/A380/A380986.seq
b3f2a2717e687a32093dc12ece35757a
A380987
Position of first appearance of n in A290106 (product of prime indices divided by product of distinct prime indices).
[ "1", "9", "25", "27", "121", "169", "289", "81", "125", "841", "961", "675", "1681", "1849", "2209", "243", "3481", "1125", "4489", "3267", "5329", "6241", "6889", "2025", "1331", "10201", "625", "7803", "11881", "12769", "16129", "729", "18769", "19321", "22201", "2197", "24649", "26569", "27889", "9801", "32041", "32761", "36481", "25947" ]
[ "nonn" ]
8
1
2
[ "A000040", "A000720", "A001221", "A001222", "A001223", "A001694", "A003557", "A003963", "A005117", "A007947", "A013929", "A046660", "A055396", "A056239", "A061395", "A064549", "A066328", "A066503", "A071625", "A112798", "A136565", "A156061", "A175508", "A178503", "A280286", "A280292", "A290106", "A304038", "A325034", "A379681", "A380955", "A380956", "A380957", "A380986", "A380987", "A380988", "A381075" ]
null
Gus Wiseman, Feb 14 2025
2025-02-18T15:34:09
oeisdata/seq/A380/A380987.seq
d079d94525970f03b182dd3ff3302cb2
A380988
Sorted positions of first appearances in A290106 (product of prime indices divided by product of distinct prime indices).
[ "1", "9", "25", "27", "81", "121", "125", "169", "243", "289", "625", "675", "729", "841", "961", "1125", "1331", "1681", "1849", "2025", "2187", "2197", "2209", "3125", "3267", "3481", "4489", "4913", "5329", "5625", "6075", "6241", "6561", "6889", "7803", "9801", "10125", "10201", "11881", "11979", "12769", "14641", "15125", "15625", "16129" ]
[ "nonn" ]
5
1
2
[ "A000040", "A000720", "A001221", "A001222", "A001223", "A001694", "A003557", "A003963", "A005117", "A007947", "A013929", "A046660", "A055396", "A056239", "A061395", "A064549", "A066328", "A066503", "A071625", "A112798", "A136565", "A156061", "A175508", "A178503", "A280286", "A280292", "A290106", "A304038", "A325034", "A379681", "A380955", "A380956", "A380957", "A380986", "A380987", "A380988", "A381075" ]
null
Gus Wiseman, Feb 18 2025
2025-02-18T15:34:06
oeisdata/seq/A380/A380988.seq
41ffa88dec34804c81a68f2337e65c86
A380989
Position of first appearance of n in A380958 (number of prime factors minus sum of distinct prime exponents).
[ "1", "6", "30", "210", "900", "7776", "27000", "279936", "810000", "9261000", "24300000", "362797056", "729000000", "13060694016", "21870000000", "408410100000", "656100000000", "16926659444736", "19683000000000", "609359740010496", "590490000000000", "18010885410000000", "17714700000000000" ]
[ "nonn" ]
33
0
2
[ "A000040", "A001221", "A001222", "A001223", "A005361", "A046660", "A051903", "A051904", "A055396", "A056239", "A061395", "A071625", "A075254", "A075255", "A076694", "A112798", "A124010", "A130091", "A130092", "A136565", "A280286", "A280292", "A290106", "A296150", "A380955", "A380956", "A380957", "A380986", "A380989", "A381075" ]
null
Gus Wiseman, Feb 18 2025
2025-02-21T09:32:17
oeisdata/seq/A380/A380989.seq
8591d20ce805f9c528e2ea623cf20116
A380990
Number of free polyominoes with n cells with at most 4 collinear cell centers on any line in the plane.
[ "1", "1", "2", "5", "11", "31", "85", "262", "764", "2255", "6341", "17221", "43994", "106205", "239367", "502611", "977791", "1771624", "2989373", "4687803", "6819069", "9234529", "11622453", "13527854", "14571011", "14643347", "13747913", "12041014", "9905945", "7763985", "5805906", "4139266", "2858796", "1971455", "1368967", "942226", "618148", "368480", "186275", "73649", "20236", "3476", "400", "96", "27", "12", "2", "1" ]
[ "nonn", "fini", "full", "nice" ]
11
1
3
[ "A000105", "A377942", "A378169", "A380990" ]
null
Dave Budd, Feb 11 2025
2025-02-12T14:23:13
oeisdata/seq/A380/A380990.seq
fe099c9506d07067330452d010606403
A380991
a(n) = largest number of cells of a polyomino with at most n collinear cell centers.
[ "1", "4", "15", "48" ]
[ "nonn", "bref", "hard", "more" ]
14
1
2
[ "A378169", "A380990", "A380991" ]
null
Dave Budd, Feb 11 2025
2025-02-12T14:23:32
oeisdata/seq/A380/A380991.seq
4f44b41b171e5e794dd6093a918902bf
A380992
Powers of two which produce a prime number when their digits are reversed.
[ "2", "16", "32", "128", "1024", "131072", "16777216", "137438953472", "35184372088832", "36028797018963968", "1180591620717411303424", "151115727451828646838272", "162259276829213363391578010288128", "174224571863520493293247799005065324265472", "1427247692705959881058285969449495136382746624" ]
[ "nonn", "base" ]
11
1
1
[ "A057708", "A380992" ]
null
Paul Duckett, Feb 11 2025
2025-02-28T15:14:02
oeisdata/seq/A380/A380992.seq
b7f7c1995b1866e5837b2147e6bb2d88
A380993
Irregular triangular array read by rows. T(n,k) is the number of ternary words of length n containing at least one copy of each letter and having exactly k inversions, n>=3, 0<=k<=floor(n^2/3).
[ "1", "2", "2", "1", "3", "6", "9", "9", "6", "3", "6", "12", "21", "27", "30", "24", "18", "9", "3", "10", "20", "38", "55", "74", "81", "80", "69", "53", "34", "17", "8", "1", "15", "30", "60", "93", "138", "174", "210", "216", "219", "195", "165", "120", "84", "48", "27", "9", "3", "21", "42", "87", "141", "222", "303", "405", "480", "546", "579", "588", "552", "498", "414", "324", "240", "162", "99", "54", "27", "9", "3" ]
[ "nonn", "tabf" ]
20
3
2
[ "A001117", "A056454", "A129529", "A380993" ]
null
Geoffrey Critzer, Feb 11 2025
2025-02-14T11:14:05
oeisdata/seq/A380/A380993.seq
1cdd90f2bf25515bd7f9aa7f4847dae1
A380994
a(n) is the largest integer with distinct digits such that every substring of length n is a prime number.
[ "7532", "89731", "863179", "8627193", "80657193", "865201937", "8502467139", "9852046317", "8975240631" ]
[ "nonn", "base", "fini", "full" ]
5
1
1
[ "A000040", "A050278", "A380994" ]
null
Gonzalo Martínez, Feb 11 2025
2025-02-11T14:05:46
oeisdata/seq/A380/A380994.seq
2f7137268a03c932e584b5d3643abe86
A380995
Integers k that are the product of 3 distinct primes, the smallest of which is larger than the 4th root of k: k = p*q*r, where p, q, r are primes and k^(1/4) < p < q < r.
[ "385", "455", "595", "1001", "1309", "1463", "1547", "1729", "1771", "2093", "2233", "2261", "2387", "2431", "2717", "3289", "3553", "4147", "4199", "4301", "4433", "4807", "5083", "5291", "5423", "5681", "5797", "5863", "6061", "6149", "6409", "6479", "6721", "6851", "6919", "7163", "7337", "7429", "7579", "7657", "7667", "7733", "7843", "8041", "8177", "8437", "8569", "8671", "8723", "8789", "8987", "9061" ]
[ "nonn" ]
32
1
1
[ "A007304", "A088382", "A115957", "A138109", "A251728", "A253567", "A290965", "A362910", "A380438", "A380995" ]
null
Matthew Goers, Feb 12 2025
2025-02-14T17:28:57
oeisdata/seq/A380/A380995.seq
264280a41500c07a58fbb74df23ca0e1
A380996
a(n) is the number of vertices in the n-fold iterated barycentric subdivision of a triangle (or 2-simplex).
[ "3", "7", "25", "121", "673", "3937", "23425", "140161", "840193", "5039617", "30234625", "181401601", "1088397313", "6530359297", "39182106625", "235092541441", "1410555052033", "8463329918977", "50779978727425", "304679870791681", "1828079221604353", "10968475323334657", "65810851927425025", "394865111539384321" ]
[ "easy", "nonn" ]
19
0
1
[ "A000400", "A007283", "A074502", "A380996" ]
null
Mikhail Lavrov, Feb 11 2025
2025-03-10T18:07:50
oeisdata/seq/A380/A380996.seq
7b8c1e3a12984ffa933d54d6477b28e1
A380997
a(n) is the least number with exactly 2 different decimal digits that is a multiple of n.
[ "10", "10", "12", "12", "10", "12", "14", "16", "18", "10", "110", "12", "13", "14", "15", "16", "17", "18", "19", "20", "21", "110", "23", "24", "25", "26", "27", "28", "29", "30", "31", "32", "330", "34", "35", "36", "37", "38", "39", "40", "41", "42", "43", "220", "45", "46", "47", "48", "49", "50", "51", "52", "53", "54", "110", "56", "57", "58", "59", "60", "61", "62", "63", "64", "65", "330", "67", "68", "69", "70", "71", "72", "73" ]
[ "nonn", "base", "look" ]
12
1
1
[ "A031955", "A380997" ]
null
Robert Israel, Feb 11 2025
2025-02-13T10:00:29
oeisdata/seq/A380/A380997.seq
08cf405bcc5536e332fed99df2e336cc
A380998
Largest k such that there are no two subsets of the k consecutive integers n..(n+k-1) with the same product.
[ "0", "4", "5", "6", "7", "6", "8", "7", "9", "8", "9", "8", "8", "7", "9", "11", "11", "10", "11", "10", "11", "13", "12", "11", "11", "10", "9", "12", "13", "12", "13", "12", "11", "14", "13", "14", "15", "14", "13", "14", "14", "13", "12", "11", "15", "17", "16", "15", "16", "15", "14", "13", "13", "12", "11", "16", "18", "17", "16", "15", "17", "16", "15", "14", "13", "18", "17", "16", "15" ]
[ "nonn" ]
12
1
2
[ "A239291", "A380998", "A380999", "A381000" ]
null
Pontus von Brömssen, Feb 11 2025
2025-02-13T09:56:54
oeisdata/seq/A380/A380998.seq
2a161536017621c9bbaaa90e6ac8d7a4
A380999
Least number k such that there exist two different subsets of {n, n+1, ..., n+A380998(n)} whose products both are equal to k.
[ "1", "6", "24", "40", "60", "72", "120", "120", "180", "180", "240", "240", "5040", "5040", "360", "432", "504", "504", "600", "600", "672", "840", "840", "840", "30240", "30240", "30240", "1120", "1260", "1260", "55440", "55440", "55440", "1680", "1680", "1800", "93600", "93600", "93600", "2160", "118800", "118800", "118800", "118800", "2700", "3024" ]
[ "nonn" ]
6
1
2
[ "A380998", "A380999", "A381000" ]
null
Pontus von Brömssen, Feb 12 2025
2025-02-13T09:57:17
oeisdata/seq/A380/A380999.seq
09d3319774cf73d0bfe4641b32b2fbe7
A381000
a(n) = A380999(n)/(n+A380998(n)).
[ "1", "1", "3", "4", "5", "6", "8", "8", "10", "10", "12", "12", "240", "240", "15", "16", "18", "18", "20", "20", "21", "24", "24", "24", "840", "840", "840", "28", "30", "30", "1260", "1260", "1260", "35", "35", "36", "1800", "1800", "1800", "40", "2160", "2160", "2160", "2160", "45", "48", "48", "48", "3024", "3024", "3024", "3024", "3360", "3360", "3360", "56", "4032" ]
[ "nonn" ]
5
1
3
[ "A380998", "A380999", "A381000" ]
null
Pontus von Brömssen, Feb 12 2025
2025-02-13T09:57:04
oeisdata/seq/A381/A381000.seq
9141a06430e6996a2b7d3335cb36bfa9
A381001
Georges Pfeffermann's 1890 bimagic square of order 8, read by rows.
[ "56", "34", "8", "57", "18", "47", "9", "31", "33", "20", "54", "48", "7", "29", "59", "10", "26", "43", "13", "23", "64", "38", "4", "49", "19", "5", "35", "30", "53", "12", "46", "60", "15", "25", "63", "2", "41", "24", "50", "40", "6", "55", "17", "11", "36", "58", "32", "45", "61", "16", "42", "52", "27", "1", "39", "22", "44", "62", "28", "37", "14", "51", "21", "3" ]
[ "nonn", "tabf", "fini", "full" ]
12
1
1
[ "A052457", "A111155", "A380966", "A381001", "A381002" ]
null
Paolo Xausa, Feb 13 2025
2025-02-14T08:10:10
oeisdata/seq/A381/A381001.seq
f8c72776e4c92b52a51186325606cb75
A381002
Gaston Tarry's 1905 trimagic square of order 128, read by rows.
[ "16132", "130", "16381", "127", "16128", "382", "15873", "387", "13632", "2750", "13761", "2627", "13508", "2882", "13373", "3007", "8452", "7810", "8701", "7807", "8448", "8062", "8193", "8067", "11072", "5310", "11201", "5187", "10948", "5442", "10813", "5567", "10028", "6314", "10197", "6231", "9944", "6486", "9769", "6571", "13080", "3222", "13289" ]
[ "nonn", "tabf", "fini", "full" ]
13
1
1
[ "A052458", "A380966", "A381001", "A381002" ]
null
Paolo Xausa, Feb 13 2025
2025-02-14T08:10:50
oeisdata/seq/A381/A381002.seq
0e653091ac9596898c65178ff522c064
A381003
Lexicographically earliest sequence with a(0) = 0 and a(n) = a(n + a(n)) - a(n - a(n)) > 0.
[ "0", "1", "1", "2", "1", "3", "1", "4", "4", "1", "5", "6", "5", "1", "6", "8", "1", "9", "1", "10", "10", "1", "11", "12", "1", "13", "13", "1", "14", "11", "15", "1", "16", "17", "1", "18", "5", "7", "18", "14", "12", "6", "20", "3", "22", "23", "15", "24", "17", "1", "18", "3", "26", "27", "20", "2", "28", "29", "1", "30", "4", "16", "31", "1", "32", "18", "33", "10", "34", "1", "35", "36", "36", "2", "21", "38" ]
[ "nonn" ]
62
0
4
[ "A110654", "A381003" ]
null
Thomas Scheuerle, Feb 11 2025
2025-03-03T13:26:36
oeisdata/seq/A381/A381003.seq
fcf84c3eb93b2fe2bd5134d5cc3375c2
A381004
Primes ending in 777.
[ "1777", "2777", "11777", "19777", "22777", "26777", "41777", "43777", "44777", "47777", "50777", "53777", "65777", "67777", "68777", "71777", "76777", "79777", "80777", "83777", "94777", "97777", "107777", "110777", "113777", "115777", "122777", "124777", "125777", "131777", "134777", "136777", "137777", "145777", "146777" ]
[ "nonn", "easy" ]
23
1
1
[ "A193552", "A381004" ]
null
Harvey P. Dale, Feb 11 2025
2025-02-13T17:16:08
oeisdata/seq/A381/A381004.seq
9f72d27fd77ff1d943649e49b5111e14
A381005
Ordered short legs of the Pythagorean triangles defined by a = 2^(4n) + 2^(2n+1), b = 2^(4n) - 2^(4n-2) - 2^(2n) - 1, c = 2^(4n) + 2^(4n-2) + 2^(2n) + 1.
[ "7", "175", "3007", "48895", "785407", "12578815", "201310207", "3221159935", "51539345407", "824632672255", "13194135339007", "211106215755775", "3377699653419007", "54043195260010495", "864691127381393407", "13835058050987196415", "221360928867334750207", "3541774862083514433535", "56668397794160864657407" ]
[ "nonn", "easy" ]
35
1
1
[ "A020884", "A381005", "A381006", "A381007", "A381008", "A381009" ]
null
Robert C. Lyons, Feb 12 2025
2025-02-26T08:50:57
oeisdata/seq/A381/A381005.seq
8dc9b625aafef4cd78a58ae0f5449ab0
A381006
Ordered long legs of the Pythagorean triangles defined by a = 2^(4n) + 2^(2n+1), b = 2^(4n) - 2^(4n-2) - 2^(2n) - 1, c = 2^(4n) + 2^(4n-2) + 2^(2n) + 1.
[ "24", "288", "4224", "66048", "1050624", "16785408", "268468224", "4295098368", "68720001024", "1099513724928", "17592194433024", "281475010265088", "4503599761588224", "72057594574798848", "1152921506754330624", "18446744082299486208", "295147905213712564224", "4722366483007084167168" ]
[ "nonn", "easy" ]
37
1
1
[ "A020883", "A381005", "A381006", "A381007", "A381008", "A381009" ]
null
Robert C. Lyons, Feb 12 2025
2025-02-26T08:51:05
oeisdata/seq/A381/A381006.seq
55153cecb0272ae5bdfabfb7a9d73dd3