Datasets:
christopher
/
oeis

Dataset card Data Studio Files
xet
Community
1
seq_id
stringlengths
7
7
seq_name
stringlengths
4
573
sequence
sequencelengths
1
348
keywords
sequencelengths
1
8
score
int64
1
2.31k
offset_a
int64
0
0
offset_b
int64
5
5
cross_references
sequencelengths
1
128
⌀
former_ids
sequencelengths
1
3
⌀
author
stringlengths
7
231
⌀
timestamp
timestamp[us]date
1999-12-11 03:00:00
2025-04-25 01:21:50
filename
stringlengths
29
29
hash
stringlengths
32
32
A002701
Coefficients for numerical differentiation.
[ "1", "1", "7", "41", "479", "59", "266681", "63397", "514639", "178939", "10410343", "18500393", "40799043101", "1411432849", "6620481151", "48409924397", "238357395880861", "339716530787", "86364397717734821", "421950627598601", "222226462279", "15392144025383" ]
[ "nonn", "frac" ]
28
0
5
[ "A002455", "A002701", "A002702" ]
[ "M4424", "N1870" ]
N. J. A. Sloane
2019-02-28T11:45:06
oeisdata/seq/A002/A002701.seq
6d94216c1f86f482aee2343f9e4afdad
A002702
Coefficients for numerical differentiation.
[ "1", "4", "120", "3024", "151200", "79200", "1513512000", "1513512000", "51459408000", "74662922880", "18068427336960", "133196739984000", "1215553449093984000", "173650492727712000", "3357242859402432000", "101013513093196704000", "2043503369875369321920000" ]
[ "nonn", "frac" ]
27
0
5
[ "A002455", "A002701", "A002702" ]
[ "M3709", "N1515" ]
N. J. A. Sloane
2019-02-28T09:44:02
oeisdata/seq/A002/A002702.seq
545015c63fdb09ed387f11edd5aa95fe
A002703
Sets with a congruence property.
[ "0", "0", "0", "2", "6", "14", "24", "46", "88", "162", "300", "562", "1056", "1982", "3742", "7082", "13438", "25574", "48768", "93198", "178480", "342392", "657918", "1266202", "2440318", "4709374", "9099504", "17602322", "34087010", "66076414", "128207976", "248983550", "483939976", "941362694", "1832519262", "3569842946", "6958934352" ]
[ "nonn" ]
63
0
5
[ "A002703", "A002704", "A002705", "A053632", "A178666", "A262567", "A262568", "A262569" ]
[ "M1598", "N0624" ]
N. J. A. Sloane
2023-10-20T12:34:26
oeisdata/seq/A002/A002703.seq
13a748da4c1a22aebc6105e87844a865
A002704
Number of sets with a congruence property.
[ "2", "26", "938", "42800", "2130458", "111557594", "6041272682", "335089258634", "18922687509962", "1083572842675610", "62744027461625648", "3666433604712457466", "215879610645469496234", "12792865816027823374874", "762278349313657804740842", "45638342462133835019322554" ]
[ "nonn" ]
47
0
5
[ "A002703", "A002704", "A002705", "A262570", "A262583", "A262584" ]
[ "M2146", "N0855" ]
N. J. A. Sloane
2023-10-19T08:48:54
oeisdata/seq/A002/A002704.seq
7079bb7ca15e391aab6358fc759e1a73
A002705
Sets with a congruence property.
[ "0", "4", "40", "468", "5828", "76260", "1032444", "14316584", "202116108", "2893451652", "41886157564", "611902123284", "9007199254740", "133439988963012", "1987795697598012", "29752813022112180", "447193795726343004", "6746237832670921768", "102105221251235572188" ]
[ "nonn" ]
40
0
5
[ "A002703", "A002704", "A002705", "A262585", "A262590" ]
[ "M3673", "N1497" ]
N. J. A. Sloane
2023-10-20T12:34:04
oeisdata/seq/A002/A002705.seq
6e1a69cd43c581fe2864b519a97e0f5b
A002706
Theta series of 6-dimensional lattice A_6^(2) (other names for this lattice or the corresponding quadratic form are LAMBDA_{3,lambda}, P_6^(5), phi_6, F_14).
[ "1", "0", "42", "56", "84", "168", "280", "336", "462", "336", "840", "672", "1176", "1176", "1386", "1008", "1848", "2016", "2058", "2520", "3528", "2408", "3108", "2688", "4760", "3024", "5880", "4592", "6468", "4704", "5040", "6720", "6930", "6832", "10080", "7224", "7812", "7392", "12600", "7056", "14280", "11760", "12040", "9408" ]
[ "nonn" ]
33
0
5
[ "A002653", "A002656", "A002706" ]
null
N. J. A. Sloane
2022-09-08T08:44:31
oeisdata/seq/A002/A002706.seq
308d7e7e59ccbd6726440077a7381615
A002707
Number of ternary trees with n nodes.
[ "1", "1", "3", "31", "8401", "100130704103", "167321084032306100365838018661441", "780729803567659232170209385771412393899822868427528396719062233553621064241305757906662806984051" ]
[ "nonn", "nice", "easy" ]
27
0
5
null
[ "M3128", "N1268" ]
N. J. A. Sloane
2014-04-18T05:56:11
oeisdata/seq/A002/A002707.seq
5213da3370f503a3004adaab850aabb6
A002708
a(n) = Fibonacci(n) mod n.
[ "0", "1", "2", "3", "0", "2", "6", "5", "7", "5", "1", "0", "12", "13", "10", "11", "16", "10", "1", "5", "5", "1", "22", "0", "0", "25", "20", "11", "1", "20", "1", "5", "13", "33", "30", "0", "36", "1", "37", "35", "1", "34", "42", "25", "20", "45", "46", "0", "36", "25", "32", "23", "52", "8", "5", "21", "40", "1", "1", "0", "1", "1", "43", "59", "60", "52", "66", "65", "44", "15", "1", "0", "72", "73", "50", "3", "2", "44", "1", "5", "7", "1", "82", "24" ]
[ "nonn", "easy", "look" ]
52
0
5
[ "A002708", "A002726", "A002752", "A023172", "A023173", "A023174", "A023182", "A161553", "A263101" ]
null
John C. Hallyburton, Jr. (hallyb(AT)evms.ENET.dec.com)
2023-10-27T19:25:09
oeisdata/seq/A002/A002708.seq
9a2bd8b8fd7984e8b2ff8d19b8fc3786
A002709
Triangulations of the disk G_{n,0}.
[ "1", "1", "1", "5", "24", "133", "846", "5661", "39556", "286000", "2123329", "16112057", "124512556", "977227830", "7772368380", "62535450861", "508271324688", "4168218286276", "34455941596060", "286864341314320", "2403705165816240", "20258850167232165", "171652324167433710", "1461462393790971585", "12498416291503945764" ]
[ "nonn" ]
36
0
5
[ "A002709", "A262586" ]
[ "M3933", "N1618" ]
N. J. A. Sloane
2024-11-23T14:27:56
oeisdata/seq/A002/A002709.seq
e7b6d63d34e4005631c58b5439e4cc1c
A002710
Triangulations of the disk G_{n,1}.
[ "1", "2", "6", "26", "147", "892", "5876", "40490", "290020", "2136488", "16113254", "123878966", "968017330", "7670113856", "61510346760", "498496979754", "4077605379276", "33629943832280", "279413323740280", "2336935584712872", "19663001667901339", "166348460274745684", "1414318445894183076", "12079654921382780966" ]
[ "nonn" ]
24
0
5
[ "A002710", "A262586" ]
[ "M1680", "N0662" ]
N. J. A. Sloane
2024-11-23T14:27:52
oeisdata/seq/A002/A002710.seq
1c1972710cb9c69d6ac1866ce6782428
A002711
Triangulations of the disk G_{n,2}.
[ "1", "5", "21", "119", "735", "4830", "33253", "237336", "1743588", "13114465", "100591491", "784428522", "6204258970", "49675571820", "402013608525", "3284214703056", "27055525967324", "224557688302164", "1876374953765620", "15774315150669075", "133345566025874055", "1132905339504465590", "9669675838370401035" ]
[ "nonn" ]
31
0
5
[ "A002711", "A210696", "A262586" ]
[ "M3916", "N1609" ]
N. J. A. Sloane
2025-01-17T10:47:00
oeisdata/seq/A002/A002711.seq
36f6a106fa78227e86718f4083ac0d17
A002712
Number of unrooted triangulations of a disk that have reflection symmetry with n interior nodes and 3 nodes on the boundary.
[ "1", "1", "1", "3", "8", "23", "68", "215", "680", "2226", "7327", "24607", "83060", "284046", "975950", "3383343", "11778308", "41269252", "145131502", "512881550", "1818259952", "6470758289", "23091680690", "82659905947", "296605398856", "1067012168350", "3846553544904", "13896522968160", "50296815014780", "182378110257354", "662384549806938" ]
[ "nonn" ]
34
0
5
[ "A002712", "A169809" ]
[ "M2746", "N1103" ]
N. J. A. Sloane
2023-04-25T07:57:59
oeisdata/seq/A002/A002712.seq
4ddb305f0e8a3502d2de9a091945cc6e
A002713
Number of unrooted triangulations of the disk with n interior nodes and 3 nodes on the boundary.
[ "1", "1", "1", "4", "16", "78", "457", "2938", "20118", "144113", "1065328", "8068332", "62297808", "488755938", "3886672165", "31269417102", "254141551498", "2084129777764", "17228043363781", "143432427097935", "1201853492038096", "10129428318995227", "85826173629557200" ]
[ "nonn" ]
25
0
5
[ "A002713", "A169808" ]
[ "M3524", "N1431" ]
N. J. A. Sloane
2021-02-25T02:39:21
oeisdata/seq/A002/A002713.seq
60792cba413f857d92d88b4eb393d563
A002714
Number of different keys with n cuts, depths between 1 and 7 and depth difference at most 1 between adjacent cut depths.
[ "1", "7", "19", "53", "149", "421", "1193", "3387", "9627", "27383", "77923", "221805", "631469", "1797957", "5119593", "14578387", "41514003", "118218823", "336653331", "958698053", "2730124261", "7774706437", "22140438345", "63050541515", "179552587883", "511322221559", "1456121982755", "4146683677885" ]
[ "nonn" ]
49
0
5
null
[ "M4366", "N1832" ]
N. J. A. Sloane
2025-04-02T09:38:13
oeisdata/seq/A002/A002714.seq
6a709a7fd7ac9e7b087fc881c02e468f
A002715
An infinite coprime sequence defined by recursion.
[ "3", "7", "23", "47", "1103", "2207", "2435423", "4870847", "11862575248703", "23725150497407", "281441383062305809756861823", "562882766124611619513723647", "158418504200047111075388369241884118003210485743490303" ]
[ "nonn" ]
35
0
5
[ "A001685", "A002715", "A003686", "A064526" ]
[ "M2683", "N1073" ]
N. J. A. Sloane
2021-12-19T10:00:58
oeisdata/seq/A002/A002715.seq
02dedf2b36f2cba7513d547191a47142
A002716
An infinite coprime sequence defined by recursion.
[ "3", "5", "13", "17", "241", "257", "65281", "65537", "4294901761", "4294967297", "18446744069414584321", "18446744073709551617", "340282366920938463444927863358058659841" ]
[ "nonn" ]
36
0
5
[ "A000215", "A001685", "A002715", "A002716", "A003686", "A064526", "A220294" ]
[ "M2488", "N0986" ]
N. J. A. Sloane
2023-10-20T09:23:04
oeisdata/seq/A002/A002716.seq
16ce1b0c365999411873fc9f21a1b663
A002717
a(n) = floor(n(n+2)(2n+1)/8).
[ "0", "1", "5", "13", "27", "48", "78", "118", "170", "235", "315", "411", "525", "658", "812", "988", "1188", "1413", "1665", "1945", "2255", "2596", "2970", "3378", "3822", "4303", "4823", "5383", "5985", "6630", "7320", "8056", "8840", "9673", "10557", "11493", "12483", "13528", "14630", "15790", "17010", "18291", "19635", "21043", "22517", "24058" ]
[ "nonn", "easy", "nice" ]
122
0
5
[ "A000004", "A000012", "A000034", "A000217", "A000292", "A002623", "A002717", "A006578", "A016777", "A032766", "A045947", "A070893", "A085691", "A135712", "A135713", "A220053" ]
[ "M3827", "N1569" ]
N. J. A. Sloane
2025-02-16T08:32:26
oeisdata/seq/A002/A002717.seq
a28652d45985a7e6b31a467a9ba4b6de
A002718
Number of bicoverings of an n-set.
[ "1", "0", "1", "8", "80", "1088", "19232", "424400", "11361786", "361058000", "13386003873", "570886397340", "27681861184474", "1511143062540976", "92091641176725504", "6219762391554815200", "462595509951068027741", "37676170944802047077248", "3343539821715571537772071", "321874499078487207168905840" ]
[ "nonn", "nice", "changed" ]
55
0
5
[ "A002718", "A002719", "A003462", "A020554", "A059443", "A059945", "A059951", "A060053" ]
[ "M4559", "N1941" ]
N. J. A. Sloane
2025-04-18T05:44:00
oeisdata/seq/A002/A002718.seq
786595d6be23d3542c777ca4dd837f04
A002719
Erroneous version of A020554.
[ "1", "3", "16", "139", "1750", "29388", "623909" ]
[ "dead" ]
16
0
5
null
[ "M3029", "N1228" ]
N. J. A. Sloane, Oct 20 2015
2025-04-18T05:46:09
oeisdata/seq/A002/A002719.seq
56a92f390f35cde2298886442980ff86
A002720
Number of partial permutations of an n-set; number of n X n binary matrices with at most one 1 in each row and column.
[ "1", "2", "7", "34", "209", "1546", "13327", "130922", "1441729", "17572114", "234662231", "3405357682", "53334454417", "896324308634", "16083557845279", "306827170866106", "6199668952527617", "132240988644215842", "2968971263911288999", "69974827707903049154", "1727194482044146637521", "44552237162692939114282" ]
[ "nonn", "easy", "nice" ]
344
0
5
[ "A000110", "A000262", "A000712", "A001048", "A002720", "A002793", "A020556", "A069223", "A073003", "A088699", "A090210", "A144084", "A160617", "A160618", "A283500", "A289192", "A364673" ]
[ "M1795", "N0708" ]
N. J. A. Sloane
2025-02-16T08:32:26
oeisdata/seq/A002/A002720.seq
d0ccf2475d9d482e19d667c518a8abae
A002721
Number of 3 X 3 X 3 arrays M_ijk (1 <= i,j,k <= 3) with entries satisfying 0 <= M_ijk <= n and all line sums equal to n.
[ "1", "12", "132", "847", "3921", "14506", "45402", "124707", "308407", "699766", "1477686", "2936517", "5540107", "9993192", "17333536", "29048541", "47220357", "74703832", "115341952", "174223731", "257989821", "375191422", "536708382", "756232687", "1050823851", "1441543026", "1954172962" ]
[ "nonn", "easy" ]
68
0
5
[ "A001496", "A002721", "A002817" ]
[ "M4864", "N2080" ]
N. J. A. Sloane
2023-10-20T12:33:20
oeisdata/seq/A002/A002721.seq
17c1fa505ad6f08bbd33c2dc2bce808a
A002722
Rotatable partitions.
[ "1", "1", "1", "2", "2", "2", "4", "6", "6", "8", "11", "13", "17", "24", "28", "36", "47", "56", "69", "94", "114", "138", "177", "218", "262", "333", "410", "496", "615", "755", "906", "1120", "1372", "1648", "2006", "2455", "2939", "3557" ]
[ "nonn", "more" ]
25
0
5
null
[ "M0238", "N0081" ]
N. J. A. Sloane
2021-07-11T18:42:37
oeisdata/seq/A002/A002722.seq
8abbfd9c1096ec597e744d2c4ce8e155
A002723
Number of rotatable partitions of [n].
[ "1", "1", "1", "1", "2", "2", "3", "3", "5", "6", "8", "9", "11", "14", "19", "22", "28", "34", "44", "52", "63", "78", "99", "119", "144", "178", "219", "265" ]
[ "nonn", "more" ]
28
0
5
[ "A002722", "A002723" ]
[ "M0272", "N0095" ]
N. J. A. Sloane
2023-10-22T16:31:34
oeisdata/seq/A002/A002723.seq
36e23cc99faeb1c2284cc91f2914a19c
A002724
Number of inequivalent n X n binary matrices, where equivalence means permutations of rows or columns.
[ "1", "2", "7", "36", "317", "5624", "251610", "33642660", "14685630688", "21467043671008", "105735224248507784", "1764356230257807614296", "100455994644460412263071692", "19674097197480928600253198363072", "13363679231028322645152300040033513414", "31735555932041230032311939400670284689732948" ]
[ "nonn", "nice" ]
106
0
5
[ "A000595", "A002623", "A002724", "A002725", "A002727", "A002728", "A006148", "A028657", "A052269", "A052271", "A052272", "A091059", "A246106", "A363845", "A363846" ]
[ "M1801", "N0711" ]
N. J. A. Sloane
2023-12-22T02:55:17
oeisdata/seq/A002/A002724.seq
fbad66e68f47cf90779a2993592d1c0b
A002725
Number of incidence matrices: n X (n+1) binary matrices under row and column permutations.
[ "1", "3", "13", "87", "1053", "28576", "2141733", "508147108", "402135275365", "1073376057490373", "9700385489355970183", "298434346895322960005291", "31479360095907908092817694945", "11474377948948020660089085281068730", "14568098446466140788730090352230460100956" ]
[ "nonn", "nice" ]
41
0
5
[ "A002623", "A002724", "A002725", "A002727", "A002728", "A006148", "A028657" ]
[ "M2957", "N1195" ]
N. J. A. Sloane
2023-03-01T11:24:34
oeisdata/seq/A002/A002725.seq
e1c57adb7b226d74d9dca4e67a298cb2
A002726
a(n) = Fibonacci(n+1) mod n.
[ "0", "0", "0", "1", "3", "1", "0", "2", "1", "9", "1", "5", "0", "8", "12", "13", "0", "5", "1", "6", "8", "13", "0", "1", "18", "14", "21", "9", "1", "19", "1", "2", "25", "1", "17", "17", "0", "2", "27", "21", "1", "5", "0", "38", "8", "1", "0", "1", "8", "24", "18", "41", "0", "31", "52", "34", "22", "31", "1", "41", "1", "2", "42", "29", "3", "35", "0", "2", "47", "69", "1", "1", "0", "38", "57", "5", "76", "31", "1", "66", "55", "43", "0", "5", "3", "44" ]
[ "nonn" ]
17
0
5
[ "A000045", "A002708", "A002726" ]
null
John C. Hallyburton, Jr. (hallyb(AT)evms.ENET.dec.com)
2018-11-07T21:50:57
oeisdata/seq/A002/A002726.seq
87dc52e9bb5818acd4f0dacd62f5b127
A002727
Number of 3 X n binary matrices up to row and column permutations.
[ "1", "4", "13", "36", "87", "190", "386", "734", "1324", "2284", "3790", "6080", "9473", "14378", "21323", "30974", "44159", "61898", "85440", "116286", "156240", "207446", "272432", "354162", "456097", "582238", "737205", "926298", "1155567", "1431892", "1763074", "2157904", "2626276", "3179278", "3829294", "4590118", "5477081" ]
[ "nonn", "nice", "easy" ]
100
0
5
[ "A000601", "A002623", "A002727", "A006148", "A006381", "A028657" ]
[ "M3460", "N1407" ]
N. J. A. Sloane
2025-03-07T12:04:18
oeisdata/seq/A002/A002727.seq
7ced58e749878d77dcf8cf2aed2f0c8a
A002728
Number of n X (n+2) binary matrices.
[ "1", "4", "22", "190", "3250", "136758", "17256831", "7216495370", "10271202313659", "49856692830176512", "826297617412284162618", "46948445432190686211183650", "9200267975562856184153936960940", "6261904454889790650636380541051266410", "14910331834338546882501064075429145637985605" ]
[ "nonn" ]
39
0
5
[ "A002623", "A002724", "A002725", "A002727", "A002728", "A006148", "A028657" ]
[ "M3593", "N1457" ]
N. J. A. Sloane
2023-03-01T11:23:56
oeisdata/seq/A002/A002728.seq
c94ca835346a8a2d0000207c3c7c6dcc
A002729
Number of equivalence classes of binary sequences of period n.
[ "1", "2", "3", "4", "6", "6", "13", "10", "24", "22", "45", "30", "158", "74", "245", "368", "693", "522", "2637", "1610", "7386", "8868", "19401", "16770", "94484", "67562", "216275", "277534", "815558", "662370", "4500267", "2311470", "8466189", "13045108", "31593285", "40937606", "159772176", "103197490", "401913697" ]
[ "nonn", "easy", "nice" ]
62
0
5
[ "A002729", "A002730", "A285548" ]
[ "M0538", "N0191" ]
N. J. A. Sloane
2023-09-02T15:45:57
oeisdata/seq/A002/A002729.seq
283338c3498d4e93869e358284047230
A002730
Number of equivalence classes of binary sequences of primitive period n.
[ "2", "1", "2", "3", "4", "8", "8", "18", "18", "38", "28", "142", "72", "234", "360", "669", "520", "2606", "1608", "7338", "8856", "19370", "16768", "94308", "67556", "216200", "277512", "815310", "662368", "4499852", "2311468", "8465496", "13045076", "31592762", "40937592", "159769394", "103197488", "401912086" ]
[ "nonn", "easy", "nice" ]
27
0
5
[ "A002729", "A002730" ]
[ "M0114", "N0044" ]
N. J. A. Sloane
2022-01-29T01:02:47
oeisdata/seq/A002/A002730.seq
151eec078c17f75726af6c6833c021b5
A002731
Numbers k such that (k^2 + 1)/2 is prime.
[ "3", "5", "9", "11", "15", "19", "25", "29", "35", "39", "45", "49", "51", "59", "61", "65", "69", "71", "79", "85", "95", "101", "121", "131", "139", "141", "145", "159", "165", "169", "171", "175", "181", "195", "199", "201", "205", "209", "219", "221", "231", "245", "261", "271", "275", "279", "289", "299", "309", "315", "321", "325", "329", "335", "345", "349", "371", "375", "379", "391", "399", "405" ]
[ "nonn", "easy", "nice" ]
61
0
5
[ "A000982", "A002731", "A010051", "A027861", "A027862", "A091277", "A116945", "A129307", "A187431", "A188546", "A188547" ]
[ "M2444", "N0971" ]
N. J. A. Sloane
2024-08-01T03:42:29
oeisdata/seq/A002/A002731.seq
56503931a6437633e53ef609b51e2895
A002732
Numbers k such that (4*k^2 + 1)/5 is prime.
[ "4", "6", "11", "14", "21", "24", "26", "29", "31", "39", "44", "46", "51", "54", "76", "79", "89", "94", "99", "101", "111", "119", "124", "129", "131", "136", "146", "149", "154", "156", "164", "176", "179", "181", "194", "201", "211", "214", "229", "231", "239", "244", "246", "254", "261", "279", "286", "294", "301", "311", "314", "319", "326", "331", "346", "349" ]
[ "nonn", "easy" ]
25
0
5
null
[ "M3281", "N1324" ]
N. J. A. Sloane
2023-10-20T09:46:15
oeisdata/seq/A002/A002732.seq
0b7f2fc18a338c99fdecad8bcbc5a38d
A002733
Numbers k such that (k^2 + 1)/10 is prime.
[ "7", "13", "17", "23", "27", "33", "37", "53", "63", "67", "77", "87", "97", "103", "113", "127", "137", "147", "153", "163", "167", "197", "223", "227", "247", "263", "267", "277", "283", "287", "297", "303", "323", "347", "363", "367", "373", "383", "397" ]
[ "nonn" ]
36
0
5
[ "A000196", "A002522", "A002731", "A002732", "A002733", "A010051" ]
[ "M4342", "N1047" ]
N. J. A. Sloane
2022-02-28T12:09:31
oeisdata/seq/A002/A002733.seq
f050d4bb2d1ef4d07fcb4c6921b8cccd
A002734
Remove squares!
[ "2", "3", "5", "6", "7", "2", "10", "11", "3", "13", "14", "15", "17", "2", "19", "5", "21", "22", "23", "6", "26", "3", "7", "29", "30", "31", "2", "33", "34", "35", "37", "38", "39", "10", "41", "42", "43", "11", "5", "46", "47", "3", "2", "51", "13", "53", "6", "55", "14", "57", "58", "59", "15", "61", "62", "7", "65", "66", "67", "17", "69", "70", "71", "2", "73", "74", "3", "19", "77", "78", "79" ]
[ "nonn" ]
25
0
5
[ "A000037", "A002734", "A007913" ]
[ "M0611", "N0222" ]
N. J. A. Sloane
2024-02-02T11:02:14
oeisdata/seq/A002/A002734.seq
2448f57544694331f0eca861dcb326c6
A002735
Related to Euler numbers, expansion of e.g.f. sec(x)*tan^2(x).
[ "4", "14", "56", "331", "1324", "12284", "49136", "663061", "2652244", "49164554", "196658216", "4798037791", "19192151164", "596372040824", "2385488163296", "91991577140521", "367966308562084", "17244625801225094", "68978503204900376", "3861296322290987251" ]
[ "nonn" ]
31
0
5
[ "A000364", "A002735", "A259688" ]
[ "M3486", "N1417" ]
N. J. A. Sloane
2025-02-03T07:21:23
oeisdata/seq/A002/A002735.seq
a23c2eb57a317191d7073b23df667459
A002736
Apéry numbers: a(n) = n^2*C(2n,n).
[ "0", "2", "24", "180", "1120", "6300", "33264", "168168", "823680", "3938220", "18475600", "85357272", "389398464", "1757701400", "7862853600", "34901442000", "153876579840", "674412197580", "2940343837200", "12759640231800", "55138611528000", "237371722628040", "1018383898440480" ]
[ "nonn", "easy", "nice" ]
126
0
5
[ "A000108", "A002736", "A005258", "A005259", "A005429", "A005430", "A086467", "A331431" ]
[ "M2136", "N0848" ]
N. J. A. Sloane
2025-01-05T19:51:32
oeisdata/seq/A002/A002736.seq
2ecfd3dce63f408a86833f486b7ccd61
A002737
a(n) = Sum_{j=0..n} (n+j)*binomial(n+j,j).
[ "0", "5", "35", "189", "924", "4290", "19305", "85085", "369512", "1587222", "6760390", "28601650", "120349800", "504131940", "2103781365", "8751023325", "36300541200", "150217371150", "620309379690", "2556724903590", "10520494818600", "43225511319900", "177361820257050", "726860987017074", "2975511197688624", "12168371410300700" ]
[ "nonn" ]
47
0
5
[ "A000108", "A002737", "A331432" ]
[ "M3975", "N1644" ]
N. J. A. Sloane
2024-03-20T15:40:24
oeisdata/seq/A002/A002737.seq
f0a6c1ebb84974ee42030362b744d12c
A002738
Coefficients for extrapolation.
[ "3", "60", "630", "5040", "34650", "216216", "1261260", "7001280", "37413090", "193993800", "981608628", "4867480800", "23728968900", "114011377200", "540972351000", "2538963567360", "11802213457650", "54396360988200", "248812984520100", "1130341536324000", "5103492036502860", "22913637714910800" ]
[ "nonn" ]
43
0
5
[ "A002738", "A002802", "A007744", "A020918", "A331431" ]
[ "M3165", "N1283" ]
N. J. A. Sloane
2022-10-18T19:14:32
oeisdata/seq/A002/A002738.seq
984ec4e3d4fa7829125c41a799fcc80f
A002739
a(n) = ((2*n-1)!/(2*n!*(n-2)!))*((n^3-3*n^2+2*n+2)/(n^2-1)).
[ "1", "10", "91", "651", "4026", "22737", "120835", "615043", "3031678", "14578928", "68747966", "319075550", "1461581460", "6621579135", "29718121635", "132302508195", "584868588150", "2569600678260", "11227927978410", "48822435838410", "211370463290220", "911509393468050", "3916793943349326", "16776146058210126", "71641860657928876" ]
[ "nonn" ]
37
0
5
[ "A002739", "A331432" ]
[ "M4732", "N2024" ]
N. J. A. Sloane
2022-10-18T19:15:18
oeisdata/seq/A002/A002739.seq
687a91378c5c7f588d726e7c49d3aeb9
A002740
Number of tree-rooted bridgeless planar maps with two vertices and n faces.
[ "0", "0", "0", "2", "15", "84", "420", "1980", "9009", "40040", "175032", "755820", "3233230", "13728792", "57946200", "243374040", "1017958725", "4242920400", "17631691440", "73078721100", "302202005490", "1247182879800", "5137916074200", "21132472200840", "86794082253450", "356013544661424", "1458583920435600", "5969389748449400" ]
[ "nonn", "easy" ]
92
0
5
[ "A002740", "A129175", "A253180" ]
[ "M2078", "N0821" ]
N. J. A. Sloane
2023-02-12T07:19:31
oeisdata/seq/A002/A002740.seq
e1354c892b7f31eacaee2517cccec150
A002741
Logarithmic numbers: expansion of the e.g.f. -log(1-x) * e^(-x).
[ "0", "1", "-1", "2", "0", "9", "35", "230", "1624", "13209", "120287", "1214674", "13469896", "162744945", "2128047987", "29943053062", "451123462672", "7245940789073", "123604151490591", "2231697509543362", "42519034050101744", "852495597142800377", "17942811657908144163", "395553947953212635718", "9114871523102565301544", "219135339782236105192745" ]
[ "sign", "easy", "nice" ]
60
0
5
[ "A000142", "A000166", "A000757", "A002741" ]
[ "M0037", "N0010" ]
N. J. A. Sloane
2022-11-28T18:51:04
oeisdata/seq/A002/A002741.seq
84d14305dfafd6a8c4265f99a6dcec56
A002742
Logarithmic numbers.
[ "2", "-6", "24", "-80", "450", "-2142", "17696", "-112464", "1232370", "-9761510", "132951192", "-1258797696", "20476388114", "-225380451870", "4261074439680", "-53438049741152", "1151146814425506", "-16199301256675974", "391615698778725080", "-6109914386833902960" ]
[ "sign" ]
51
0
5
[ "A002741", "A002742" ]
[ "M1672", "N0658" ]
N. J. A. Sloane
2022-09-26T20:33:04
oeisdata/seq/A002/A002742.seq
b993c26f7ec187daf8e560e3f1da0e12
A002743
Sum of logarithmic numbers.
[ "1", "1", "2", "24", "-11", "1085", "-2542", "64344", "-56415", "4275137", "-10660486", "945005248", "-6010194555", "147121931021", "88135620922", "23131070531152", "-120142133444319", "12007306976370081", "-103897545509370542", "4923827766711915784", "-19471338470911446283", "1203786171449486366205" ]
[ "sign" ]
34
0
5
[ "A000203", "A002743", "A002745" ]
[ "M2132", "N0845" ]
N. J. A. Sloane
2023-10-20T09:36:27
oeisdata/seq/A002/A002743.seq
5abdd7c8b5808911f5d4fa0df85b51b1
A002744
Sum of logarithmic numbers.
[ "1", "0", "1", "10", "-17", "406", "-1437", "20476", "-44907", "1068404", "-5112483", "230851094", "-1942311373", "31916614874", "-27260241361", "3826126294680", "-37957167335671", "2169009251237640", "-25847377785179111", "858747698098918338", "-5611513985867158697", "154094365406716365118" ]
[ "sign" ]
35
0
5
[ "A000005", "A002744", "A002746", "A318249" ]
[ "M4682", "N2001" ]
N. J. A. Sloane
2020-05-13T07:03:37
oeisdata/seq/A002/A002744.seq
f0ad94dd2922477045d586e1eac822fc
A002745
Sum of logarithmic numbers.
[ "1", "5", "20", "96", "469", "3145", "20684", "173544", "1557105", "16215253", "159346604", "2230085528", "26985045333", "368730610729", "5628888393652", "97987283458928", "1475486672174337", "29097611462122437", "505383110562327268", "10970329921706735216" ]
[ "nonn" ]
38
0
5
[ "A000203", "A002743", "A002745" ]
[ "M3909", "N1604" ]
N. J. A. Sloane
2023-10-20T09:37:23
oeisdata/seq/A002/A002745.seq
4494481abf7d64f47af3b6cdd67ef2df
A002746
Sum of logarithmic numbers.
[ "1", "4", "13", "50", "203", "1154", "6627", "49356", "403293", "3858376", "33929377", "460614670", "5168544119", "64518640406", "946910125319", "16124114481720", "221243980745433", "4261440137319852", "68524390012831189", "1477309421907315082" ]
[ "nonn" ]
36
0
5
[ "A000005", "A002744", "A002746", "A318249" ]
[ "M3468", "N1411" ]
N. J. A. Sloane
2023-10-20T09:38:10
oeisdata/seq/A002/A002746.seq
0a1e1acf7905fa5e7c99c2b82a79ecb8
A002747
Logarithmic numbers.
[ "1", "-2", "9", "-28", "185", "-846", "7777", "-47384", "559953", "-4264570", "61594841", "-562923252", "9608795209", "-102452031878", "2017846993905", "-24588487650736", "548854382342177", "-7524077221125234", "187708198761024553", "-2859149344027588940", "78837443479630312281", "-1320926996940746090302" ]
[ "sign" ]
96
0
5
[ "A000166", "A000522", "A002747", "A087208" ]
[ "M1924", "N0759" ]
N. J. A. Sloane
2024-10-19T18:33:52
oeisdata/seq/A002/A002747.seq
de814f45c209df52c46e0b41199ed08b
A002748
Sum of logarithmic numbers.
[ "1", "2", "3", "26", "13", "1074", "-1457", "61802", "7929", "4218722", "-6385349", "934344762", "-5065189307", "141111736466", "235257551943", "23219206152074", "-97011062913167", "11887164842925762", "-91890238533000461", "4819930221202545242", "-14547510704199530499", "1184314832978574919922" ]
[ "sign", "easy" ]
28
0
5
[ "A002748", "A002750" ]
[ "M0923", "N0347" ]
N. J. A. Sloane
2015-08-02T20:23:18
oeisdata/seq/A002/A002748.seq
3966a47b2ecdbc5dfc9c581a5fadac92
A002749
Sum of logarithmic numbers.
[ "1", "1", "1", "11", "-7", "389", "-1031", "19039", "-24431", "1023497", "-4044079", "225738611", "-1711460279", "29974303501", "4656373513", "3798866053319", "-34131041040991", "2131052083901969", "-23678368533941471", "832900320313739227", "-4752766287768240359", "148482851420849206421" ]
[ "sign" ]
27
0
5
null
[ "M4767", "N2037" ]
N. J. A. Sloane
2023-10-20T09:39:05
oeisdata/seq/A002/A002749.seq
ed6b908463956001ce423444a95bf1d2
A002750
Sum of logarithmic numbers.
[ "1", "4", "15", "76", "373", "2676", "17539", "152860", "1383561", "14658148", "143131351", "2070738924", "24754959805", "341745565396", "5260157782923", "92358395065276", "1377499388715409", "27622124789948100", "476285499100204831", "10464946811144407948", "222724531608924013701" ]
[ "nonn" ]
33
0
5
[ "A000203", "A002750" ]
[ "M3506", "N1422" ]
N. J. A. Sloane
2024-11-19T10:35:16
oeisdata/seq/A002/A002750.seq
d90277af72346c13be7430e033b5bb96
A002751
Sum of logarithmic numbers.
[ "1", "3", "9", "37", "153", "951", "5473", "42729", "353937", "3455083", "30071001", "426685293", "4707929449", "59350096287", "882391484913", "15177204356401", "205119866263713", "4040196156574419", "64262949875511337", "1408785031894483893", "29514546353782633401", "593055713389216814983" ]
[ "nonn" ]
27
0
5
null
[ "M2821", "N1135" ]
N. J. A. Sloane
2023-10-20T09:40:35
oeisdata/seq/A002/A002751.seq
09469c29fb238ecaef2631c6e18f33bb
A002752
a(n) = Fibonacci(n-1) mod n.
[ "0", "1", "1", "2", "3", "5", "1", "5", "3", "4", "0", "5", "1", "9", "2", "2", "1", "13", "0", "1", "3", "12", "1", "1", "18", "15", "1", "26", "0", "29", "0", "29", "12", "2", "22", "17", "1", "1", "29", "26", "0", "13", "1", "13", "33", "2", "1", "1", "21", "49", "37", "18", "1", "23", "47", "13", "39", "30", "0", "41", "0", "1", "62", "34", "8", "49", "1", "5", "3", "54", "0", "1", "1", "39", "7", "2", "74" ]
[ "nonn" ]
21
0
5
[ "A000045", "A002708", "A002752", "A352747" ]
null
John C. Hallyburton, Jr. (hallyb(AT)evms.ENET.dec.com)
2022-04-11T12:54:32
oeisdata/seq/A002/A002752.seq
b869eb8fbd15d67dbc7ad1dc68158af2
A002753
Coefficients of elliptic function sn.
[ "1", "1", "14", "135", "5478", "165826", "13180268", "834687179", "109645021894", "11966116940238", "2347836365864484", "393938089395885894", "107947764316226205276", "25835579116799316507780" ]
[ "nonn" ]
38
0
5
[ "A002753", "A006089", "A060628" ]
[ "M4944", "N2117" ]
N. J. A. Sloane
2023-10-20T09:42:47
oeisdata/seq/A002/A002753.seq
a2073703bd1c683eacc23255e885dd05
A002754
Related to coefficient of m in Jacobi elliptic function cn(z, m).
[ "0", "0", "4", "44", "408", "3688", "33212", "298932", "2690416", "24213776", "217924020", "1961316220", "17651846024", "158866614264", "1429799528428", "12868195755908", "115813761803232", "1042323856229152", "9380914706062436", "84428232354561996", "759854091191058040" ]
[ "nonn", "easy" ]
51
0
5
[ "A002754", "A014832", "A060627" ]
[ "M3680", "N1501" ]
N. J. A. Sloane
2023-08-23T08:35:08
oeisdata/seq/A002/A002754.seq
8ba5e799f4f6618d0c25de89993309d1
A002755
Number of bipartite partitions of n white objects and 6 black ones.
[ "11", "30", "77", "162", "323", "589", "1043", "1752", "2876", "4571", "7128", "10860", "16306", "24051", "35040", "50355", "71609", "100697", "140349", "193784", "265505", "360889", "487214", "653243", "870613", "1153322", "1519658", "1991689", "2597762", "3372107", "4358198", "5608418", "7188632" ]
[ "nonn" ]
47
0
5
[ "A002755", "A005380", "A054225" ]
[ "M4784", "N2041" ]
N. J. A. Sloane
2024-01-01T08:01:26
oeisdata/seq/A002/A002755.seq
e86112a3f8f498e1809b31168bfc0ded
A002756
Number of bipartite partitions of n white objects and 7 black ones.
[ "15", "45", "118", "257", "522", "975", "1752", "2998", "4987", "8043", "12693", "19584", "29719", "44324", "65210", "94642", "135805", "192699", "270822", "377048", "520624", "713123", "969784", "1309646", "1757447", "2343931", "3108553", "4100220", "5380964", "7027376", "9135769", "11824507" ]
[ "nonn" ]
42
0
5
[ "A002756", "A005380", "A054225" ]
[ "M4964", "N2129" ]
N. J. A. Sloane
2024-01-01T08:01:21
oeisdata/seq/A002/A002756.seq
93e32f06965929531d015be3593fecbc
A002757
Number of bipartite partitions of n white objects and 8 black ones.
[ "22", "67", "181", "401", "831", "1576", "2876", "4987", "8406", "13715", "21893", "34134", "52327", "78785", "116982", "171259", "247826", "354482", "502090", "704265", "979528", "1351109", "1849932", "2514723", "3396262", "4557867", "6081466", "8068930", "10650479", "13987419", "18283999" ]
[ "nonn" ]
41
0
5
[ "A002757", "A005380", "A054225" ]
[ "M5123", "N2219" ]
N. J. A. Sloane
2024-01-01T08:01:16
oeisdata/seq/A002/A002757.seq
45fa27d1f18a07cb2c77cf8d05a21dd0
A002758
Number of bipartite partitions of n white objects and 9 black ones.
[ "30", "97", "267", "608", "1279", "2472", "4571", "8043", "13715", "22652", "36535", "57568", "89079", "135384", "202747", "299344", "436597", "629364", "897970", "1268634", "1776562", "2466961", "3399463", "4650218", "6318429", "8529869", "11446563", "15272827", "20269135", "26762094" ]
[ "nonn" ]
41
0
5
[ "A002758", "A005380", "A054225" ]
[ "M5209", "N2265" ]
N. J. A. Sloane
2024-01-01T08:01:11
oeisdata/seq/A002/A002758.seq
7500a0bac551f348f27ae02bcb032920
A002759
Number of bipartite partitions of n white objects and 10 black ones.
[ "42", "139", "392", "907", "1941", "3804", "7128", "12693", "21893", "36535", "59521", "94664", "147794", "226524", "342006", "508866", "747753", "1085635", "1559725", "2218272", "3126541", "4368724", "6056705", "8333955", "11388614", "15460291", "20859497", "27979454", "37324367", "49529018" ]
[ "nonn" ]
41
0
5
[ "A002759", "A005380", "A054225" ]
[ "M5278", "N2295" ]
N. J. A. Sloane
2024-01-01T08:01:07
oeisdata/seq/A002/A002759.seq
68a799eaba0e835985a19d49da15dc86
A002760
Squares and cubes.
[ "0", "1", "4", "8", "9", "16", "25", "27", "36", "49", "64", "81", "100", "121", "125", "144", "169", "196", "216", "225", "256", "289", "324", "343", "361", "400", "441", "484", "512", "529", "576", "625", "676", "729", "784", "841", "900", "961", "1000", "1024", "1089", "1156", "1225", "1296", "1331", "1369", "1444", "1521", "1600", "1681", "1728", "1764", "1849" ]
[ "nonn" ]
55
0
5
[ "A000290", "A000578", "A002117", "A002760", "A013661", "A013664", "A075052", "A131799" ]
null
N. J. A. Sloane
2024-08-09T10:07:24
oeisdata/seq/A002/A002760.seq
5f41a9c403521113faeaefc4113bdce2
A002761
Number of ways of getting a royal flush, other straight flush, 4 of a kind, full house, other flush, other straight, 3 of a kind, 2 pair, a pair or nothing in 5-card poker.
[ "4", "36", "624", "3744", "5108", "10200", "54912", "123552", "1098240", "1302540" ]
[ "fini", "full", "nonn" ]
16
0
5
[ "A002761", "A002806", "A002847" ]
null
N. J. A. Sloane, Koreen M Mielke (mielkk72(AT)VAXA.CIS.UWOSH.EDU)
2019-04-09T05:12:46
oeisdata/seq/A002/A002761.seq
c4de14ba0a17d26aabdb7a3f66943851
A002762
Number of bipartite partitions.
[ "4", "9", "21", "40", "74", "125", "209", "330", "515", "778", "1160", "1690", "2439", "3457", "4857", "6735", "9264", "12607", "17040", "22826", "30391", "40165", "52788", "68938", "89589", "115778", "148957", "190714", "243184", "308746", "390539", "492071", "617900", "773175", "964443", "1199168", "1486724", "1837806" ]
[ "nonn" ]
22
0
5
null
[ "M3362", "N1354" ]
N. J. A. Sloane
2023-10-20T10:05:18
oeisdata/seq/A002/A002762.seq
61b93b0b2c4f385f81eda1274a6fd6d3
A002763
Number of bipartite partitions.
[ "4", "11", "26", "52", "98", "171", "289", "467", "737", "1131", "1704", "2515", "3661", "5246", "7430", "10396", "14405", "19760", "26884", "36269", "48583", "64614", "85399", "112170", "146526", "190362", "246099", "316621", "405556", "517224", "657012", "831320", "1048055", "1316611", "1648486", "2057324", "2559719", "3175309" ]
[ "nonn" ]
33
0
5
[ "A002763", "A082775", "A129306" ]
[ "M3414", "N1380" ]
N. J. A. Sloane
2021-12-20T20:18:42
oeisdata/seq/A002/A002763.seq
f036f87fb3e0c8126ee18e04f2df238e
A002764
Number of bipartite partitions.
[ "7", "18", "44", "88", "169", "296", "507", "824", "1314", "2029", "3083", "4578", "6714", "9676", "13795", "19408", "27053", "37302", "51029", "69180", "93139", "124447", "165259", "218021", "286068", "373207", "484512", "625845", "804840", "1030369", "1313823", "1668466", "2111101", "2661365", "3343811", "4187191" ]
[ "nonn" ]
19
0
5
null
[ "M4359", "N1827" ]
N. J. A. Sloane
2023-10-20T10:06:05
oeisdata/seq/A002/A002764.seq
bfa84bffd399ded981fd790c22658566
A002765
Number of bipartite partitions.
[ "8", "23", "57", "119", "231", "415", "719", "1189", "1915", "2997", "4595", "6898", "10198", "14833", "21303", "30211", "42393", "58869", "81028", "110551", "149683", "201160", "268539", "356167", "469630", "615712", "803029", "1042051", "1345896", "1730473", "2215561", "2825037", "3588364", "4541036" ]
[ "nonn" ]
20
0
5
null
[ "M4495", "N1902" ]
N. J. A. Sloane
2023-10-20T10:06:49
oeisdata/seq/A002/A002765.seq
96882a7064db9712f5e3562d417e4c89
A002766
Number of bipartite partitions.
[ "4", "10", "23", "45", "83", "142", "237", "377", "588", "892", "1330", "1943", "2804", "3982", "5595", "7768", "10686", "14555", "19674", "26371", "35112", "46424", "61015", "79705", "103579", "133883", "172243", "220551", "281212", "357043", "451592", "568997", "714424", "893921", "1114930", "1386187" ]
[ "nonn", "more" ]
19
0
5
null
[ "M3387", "N1367" ]
N. J. A. Sloane
2023-10-20T10:07:33
oeisdata/seq/A002/A002766.seq
27b624c7aa3f43702ff29a6064a6ebc7
A002767
Number of bipartite partitions.
[ "5", "12", "28", "54", "100", "170", "284", "450", "702", "1062", "1583", "2308", "3329", "4720", "6628", "9190", "12634", "17189", "23219", "31092", "41371", "54651", "71782", "93695", "121684", "157169", "202080", "258579", "329509", "418096", "528518", "665521", "835170", "1044408", "1301949", "1617830" ]
[ "nonn" ]
19
0
5
null
[ "M3820", "N1564" ]
N. J. A. Sloane
2023-10-20T10:08:30
oeisdata/seq/A002/A002767.seq
b968ecc4102805c8a782670060434403
A002768
Number of bipartite partitions.
[ "5", "13", "30", "59", "109", "187", "312", "497", "775", "1176", "1753", "2561", "3694", "5245", "7366", "10223", "14056", "19137", "25853", "34637", "46092", "60910", "80009", "104462", "135674", "175274" ]
[ "nonn" ]
19
0
5
null
[ "M3831", "N1571" ]
N. J. A. Sloane
2023-10-20T10:09:10
oeisdata/seq/A002/A002768.seq
990ce24fa32e9354f48c998a9ae78e8a
A002769
Discriminants of totally real quartic fields (see comments).
[ "725", "1125", "1600", "2000", "2048", "2225", "2304", "2525", "2624", "3600", "4205", "4225", "4352", "4400", "4525", "4752", "4913", "5125", "5225", "5725", "6125", "7056", "7168", "7225", "7232", "7488", "7600", "7625", "8000", "8112", "8525", "8725", "8768", "8957", "9225", "9248", "9792", "10025", "10304", "10309", "10512" ]
[ "nonn", "nice" ]
25
0
5
[ "A002769", "A023680" ]
[ "M5475", "N2371" ]
N. J. A. Sloane
2022-01-29T01:02:13
oeisdata/seq/A002/A002769.seq
82a80d409997f009222ccfda00284d52
A002770
Integers connected with coefficients in expansion of Weierstrass P-function.
[ "-1", "5", "253", "39299", "13265939", "8616924013", "9833937781275", "18382040180023477", "53311001020080183933", "229658082900486063068939", "1418085582879166915943461879", "12182969300667152908506740224429", "141998788870155117956738989275999795" ]
[ "sign", "easy", "nice" ]
44
0
5
[ "A002172", "A002306", "A002770", "A047817" ]
[ "M4033", "N1675" ]
N. J. A. Sloane
2018-02-26T00:53:26
oeisdata/seq/A002/A002770.seq
ce6914f79166fcf76fff646a76d1c701
A002771
Number of terms in a skew determinant: a(n) = (A000085(n) + A081919(n))/2.
[ "1", "2", "4", "13", "41", "226", "1072", "9374", "60958", "723916", "5892536", "86402812", "837641884", "14512333928", "162925851376", "3252104882056", "41477207604872", "937014810365584", "13380460644770848", "337457467862898896", "5333575373478669136", "148532521250931168352" ]
[ "nonn" ]
50
0
5
[ "A000085", "A002771", "A002772", "A081919" ]
[ "M1269", "N0488" ]
N. J. A. Sloane
2023-10-20T11:54:30
oeisdata/seq/A002/A002771.seq
fdebdbc786962a37a0dfb38e51603893
A002772
Number of terms in a bordered skew determinant.
[ "2", "6", "22", "101", "546", "3502", "25586", "214062", "1987516", "20599076", "232482372", "2876191276", "38228128472", "549706132536", "8408517839416", "137788390312712", "2383879842920976", "43846851982943152", "846470648320690736", "17266870434276713616", "367937854493289655072" ]
[ "nonn" ]
36
0
5
[ "A002771", "A002772", "A243107" ]
[ "M1664", "N0654" ]
N. J. A. Sloane
2023-10-20T11:52:47
oeisdata/seq/A002/A002772.seq
6f458d9cd45773a3612f7d623fdc0b08
A002773
Number of nonisomorphic simple matroids (or geometries) with n points.
[ "1", "1", "1", "2", "4", "9", "26", "101", "950", "376467" ]
[ "nonn", "nice", "more" ]
84
0
5
[ "A002773", "A055545", "A056642", "A058730" ]
[ "M1197", "N0462" ]
N. J. A. Sloane
2025-02-16T08:32:26
oeisdata/seq/A002/A002773.seq
5b012cfa318d91e395565e29f79fd895
A002774
Number of bipartite partitions of n white objects and n black ones.
[ "1", "2", "9", "31", "109", "339", "1043", "2998", "8406", "22652", "59521", "151958", "379693", "927622", "2224235", "5236586", "12130780", "27669593", "62229990", "138095696", "302673029", "655627975", "1404599867", "2977831389", "6251060785", "12999299705", "26791990052", "54750235190", "110977389012" ]
[ "nonn" ]
101
0
5
[ "A000041", "A000070", "A000291", "A000412", "A000465", "A000491", "A002755", "A002756", "A002757", "A002758", "A002759", "A002774", "A005380", "A054225", "A219554", "A219727", "A277239" ]
[ "M1925", "N0760" ]
N. J. A. Sloane
2025-03-24T12:47:27
oeisdata/seq/A002/A002774.seq
49f3b4567390afd158c54cb85860b557
A002775
a(n) = n^2 * n!.
[ "0", "1", "8", "54", "384", "3000", "25920", "246960", "2580480", "29393280", "362880000", "4829932800", "68976230400", "1052366515200", "17086945075200", "294226732800000", "5356234211328000", "102793666719744000", "2074369080655872000", "43913881247588352000", "973160803270656000000", "22531105497723863040000" ]
[ "nonn", "easy", "changed" ]
66
0
5
[ "A000142", "A000290", "A001563", "A002775", "A047922", "A091363", "A091364", "A163931", "A367731", "A367732" ]
[ "M4540", "N1927" ]
N. J. A. Sloane
2025-04-18T07:07:33
oeisdata/seq/A002/A002775.seq
d410b417424f41cb3a9754d23a3ddb07
A002776
Terms in certain determinants.
[ "1", "5", "34", "258", "2136", "19320", "190800", "2051280", "23909760", "300827520", "4067884800", "58877280000", "908666035200", "14901260774400", "258832346572800", "4748165630208000", "91746433658880000", "1862735060938752000", "39649900359573504000", "883021783867711488000" ]
[ "nonn", "easy", "nice" ]
43
0
5
[ "A002776", "A047922" ]
[ "M3972", "N1642" ]
N. J. A. Sloane
2022-04-17T10:24:08
oeisdata/seq/A002/A002776.seq
8409825d5ee68f5d6bbddc607e2ee6fd
A002777
Restricted permutations.
[ "1", "0", "0", "0", "4", "16", "80", "672", "4896", "49920", "460032", "5598720", "62584320", "885381120", "11644323840", "187811205120", "2841958748160", "51481298534400", "881192033648640", "17714783352913920", "338434210452602880", "7477275543168614400" ]
[ "nonn", "easy" ]
38
0
5
[ "A002777", "A003471" ]
[ "M3526", "N1432" ]
N. J. A. Sloane
2024-04-20T15:18:26
oeisdata/seq/A002/A002777.seq
e2725379a3edd4e0a0d68a4679908ead
A002778
Numbers whose square is a palindrome.
[ "0", "1", "2", "3", "11", "22", "26", "101", "111", "121", "202", "212", "264", "307", "836", "1001", "1111", "2002", "2285", "2636", "10001", "10101", "10201", "11011", "11111", "11211", "20002", "20102", "22865", "24846", "30693", "100001", "101101", "110011", "111111", "200002", "798644", "1000001", "1001001" ]
[ "base", "nonn", "nice", "easy" ]
94
0
5
[ "A000290", "A002113", "A002778", "A002779", "A003166", "A016113", "A029984", "A136522", "A263607" ]
[ "M0907", "N0342" ]
N. J. A. Sloane
2025-04-02T18:04:06
oeisdata/seq/A002/A002778.seq
8f41049d09c7bfb214d481747f5a5e81
A002779
Palindromic squares.
[ "0", "1", "4", "9", "121", "484", "676", "10201", "12321", "14641", "40804", "44944", "69696", "94249", "698896", "1002001", "1234321", "4008004", "5221225", "6948496", "100020001", "102030201", "104060401", "121242121", "123454321", "125686521", "400080004", "404090404", "522808225" ]
[ "nonn", "base", "nice", "easy" ]
106
0
5
[ "A000290", "A002113", "A002778", "A002779", "A010052", "A027829", "A028817", "A029734", "A029738", "A029806", "A029983", "A029985", "A029987", "A029989", "A029991", "A029993", "A029995", "A029997", "A029999", "A030074", "A030075", "A057136", "A136522" ]
[ "M3371", "N1358" ]
N. J. A. Sloane
2025-02-16T08:32:26
oeisdata/seq/A002/A002779.seq
9654a91c691d198227e88aedb184abe2
A002780
Numbers whose cube is a palindrome.
[ "0", "1", "2", "7", "11", "101", "111", "1001", "2201", "10001", "10101", "11011", "100001", "101101", "110011", "1000001", "1001001", "1100011", "10000001", "10011001", "10100101", "11000011", "100000001", "100010001", "100101001", "101000101", "110000011", "1000000001", "1000110001" ]
[ "base", "nonn", "nice" ]
42
0
5
[ "A002780", "A002781" ]
[ "M1736", "N0688" ]
N. J. A. Sloane
2022-08-02T15:39:51
oeisdata/seq/A002/A002780.seq
c1c166524a6789f9de98b0e23e2e0ab3
A002781
Palindromic cubes.
[ "0", "1", "8", "343", "1331", "1030301", "1367631", "1003003001", "10662526601", "1000300030001", "1030607060301", "1334996994331", "1000030000300001", "1033394994933301", "1331399339931331", "1000003000003000001", "1003006007006003001", "1331039930399301331" ]
[ "base", "nonn", "nice" ]
35
0
5
[ "A000578", "A002113", "A002780", "A002781" ]
[ "M4583", "N1954" ]
N. J. A. Sloane
2025-01-05T19:51:32
oeisdata/seq/A002/A002781.seq
6abf1111185ab3b5c9346cf94c61dd6f
A002782
Concatenate the natural numbers, then partition into minimal strings so that each term divides the next.
[ "1", "2", "34", "5678", "9101112131415161718192021222324252627282930313233343536" ]
[ "nonn", "base", "nice" ]
34
0
5
[ "A002782", "A007376", "A007908", "A258227", "A263623" ]
[ "M2157", "N0859" ]
N. J. A. Sloane
2022-01-29T01:01:43
oeisdata/seq/A002/A002782.seq
51e7f8dc1d610afe18238ac3c41f38fd
A002783
a(n) = 2*(3^n - 2^n) + 1.
[ "1", "3", "11", "39", "131", "423", "1331", "4119", "12611", "38343", "116051", "350199", "1054691", "3172263", "9533171", "28632279", "85962371", "258018183", "774316691", "2323474359", "6971471651", "20916512103", "62753730611", "188269580439", "564825518531", "1694510110023", "5083597438931", "15250926534519" ]
[ "nonn", "easy" ]
68
0
5
[ "A002783", "A027649", "A090326", "A095121" ]
[ "M2892", "N1159" ]
N. J. A. Sloane
2024-05-18T14:53:07
oeisdata/seq/A002/A002783.seq
864c3a036268076e33ca7aee0c9a9093
A002784
A problem in parity.
[ "1", "1", "1", "2", "3", "1", "1", "4", "5", "1", "3", "1", "3", "1", "1", "8", "15", "3", "7", "4", "5", "2", "3", "3", "6", "2", "3", "2", "3", "1", "1", "16", "19", "7", "10", "5", "15", "4", "5", "7", "15", "3", "7", "4", "5", "2", "3", "5", "13", "3", "5", "4", "7", "1", "3", "3", "5", "2", "3", "1", "3", "1", "1", "32", "47", "11", "31", "14", "21", "6", "15", "11", "31", "7", "9", "7", "12", "3", "7", "12", "21", "7", "15", "4", "11", "4", "5", "7", "15", "2", "7", "4", "5" ]
[ "nonn" ]
19
0
5
[ "A002784", "A050169", "A073166" ]
[ "M0401", "N0154" ]
N. J. A. Sloane
2023-10-20T21:12:44
oeisdata/seq/A002/A002784.seq
14fa407c2390a4ed5b2e506ec14d42d7
A002785
Number of self-complementary oriented graphs with n nodes.
[ "1", "1", "2", "2", "8", "12", "88", "176", "2752", "8784", "279968", "1492288", "95458560", "872687552", "111698291584", "1787154671104", "457509297625088", "13013584213369088", "6662951988432581120", "341143107490935724032", "349330527429800077778944", "32519496073514216703585280" ]
[ "nonn", "nice", "easy" ]
40
0
5
[ "A000171", "A002785", "A003086", "A005639" ]
[ "M0375", "N0141" ]
N. J. A. Sloane
2021-01-07T15:09:19
oeisdata/seq/A002/A002785.seq
0cd45fdd1b63eab6ffda071b721ad169
A002786
Semigroups of order n with 1 idempotent, considered to be equivalent when they are isomorphic or anti-isomorphic (by reversal of the operator).
[ "1", "2", "5", "19", "132", "3107", "623615", "1834861133", "52976551026562", "12417619575092896741" ]
[ "nonn", "nice", "hard" ]
28
0
5
[ "A002786", "A058123" ]
[ "M1522", "N0596" ]
N. J. A. Sloane
2025-02-16T08:32:26
oeisdata/seq/A002/A002786.seq
b22c27083a1b5da38073ea8009e44428
A002787
Number of semigroups of order n with 2 idempotents, considered to be equivalent when they are isomorphic or anti-isomorphic (by reversal of the operator).
[ "2", "7", "37", "216", "1780", "32652", "4665709", "12710266442", "381279977009776" ]
[ "nonn", "hard", "more" ]
33
0
5
[ "A002787", "A058123" ]
[ "M1802", "N0712" ]
N. J. A. Sloane
2025-02-16T08:32:26
oeisdata/seq/A002/A002787.seq
eeaac66d5bd5ff35a8c399ec25bf9bcf
A002788
Idempotent semigroups of order n, considered to be equivalent when they are isomorphic or anti-isomorphic (by reversal of the operator).
[ "1", "1", "2", "6", "26", "135", "875", "6749", "60601", "618111", "7033090" ]
[ "nonn", "nice", "hard" ]
27
0
5
[ "A001423", "A002788", "A058123" ]
[ "M1679", "N0661" ]
N. J. A. Sloane
2025-02-16T08:32:26
oeisdata/seq/A002/A002788.seq
8658fe8fa668091ae65c3ea138e4378a
A002789
Number of integer points in a certain quadrilateral scaled by a factor of n.
[ "2", "4", "7", "11", "16", "21", "28", "35", "43", "52", "62", "72", "84", "96", "109", "123", "138", "153", "170", "187", "205", "224", "244", "264", "286", "308", "331", "355", "380", "405", "432", "459", "487", "516", "546", "576", "608", "640", "673", "707", "742", "777", "814", "851", "889", "928", "968", "1008", "1050", "1092", "1135", "1179", "1224", "1269" ]
[ "nonn" ]
29
0
5
[ "A002789", "A168668", "A242771", "A242774" ]
[ "M1039", "N0390" ]
N. J. A. Sloane
2015-10-23T19:38:40
oeisdata/seq/A002/A002789.seq
22b400b8bb8a12d4ae5381e4bcfb35fb
A002790
Denominators of Cauchy numbers of second type (= Bernoulli numbers B_n^{(n)}).
[ "1", "2", "6", "4", "30", "12", "84", "24", "90", "20", "132", "24", "5460", "840", "360", "16", "1530", "180", "7980", "840", "13860", "440", "1656", "720", "81900", "6552", "216", "112", "3480", "240", "114576", "7392", "117810", "2380", "1260", "72", "3838380", "207480", "32760", "560", "568260", "27720", "238392", "55440", "869400", "2576", "236880" ]
[ "nonn", "frac", "nice", "easy" ]
112
0
5
[ "A002206", "A002207", "A002208", "A002209", "A002657", "A002790", "A006232", "A006233", "A075266", "A075267", "A262235" ]
[ "M1559", "N0608" ]
N. J. A. Sloane
2025-01-05T19:51:32
oeisdata/seq/A002/A002790.seq
c0a0bff024547b4894fa3a5bc01e35a4
A002791
a(n) = Sum_{d|n, d <= 4} d^2 + 4*Sum_{d|n, d>4} d.
[ "1", "5", "10", "21", "21", "38", "29", "53", "46", "65", "45", "102", "53", "89", "90", "117", "69", "146", "77", "161", "122", "137", "93", "230", "121", "161", "154", "217", "117", "278", "125", "245", "186", "209", "189", "354", "149", "233", "218", "353", "165", "374", "173", "329", "306", "281", "189", "486", "225", "365", "282", "385", "213", "470", "285", "473", "314", "353", "237", "662", "245", "377", "410", "501", "333", "566", "269", "497" ]
[ "nonn" ]
34
0
5
[ "A002659", "A002660", "A002791", "A242639" ]
[ "M3798", "N1550" ]
N. J. A. Sloane
2019-08-17T15:48:44
oeisdata/seq/A002/A002791.seq
e03da52eb4efc14db2bcca75d127286e
A002792
Erroneous version of A108919.
[ "1", "0", "1", "1", "13", "51", "601", "4806", "39173", "775351" ]
[ "dead" ]
22
0
5
null
[ "M4897", "N2099" ]
N. J. A. Sloane
2023-10-20T21:13:50
oeisdata/seq/A002/A002792.seq
3b40465e570318fe3c4bec96bb419791
A002793
a(n) = 2n*a(n-1) - (n-1)^2*a(n-2).
[ "0", "1", "4", "20", "124", "920", "7940", "78040", "859580", "10477880", "139931620", "2030707640", "31805257340", "534514790680", "9591325648580", "182974870484120", "3697147584561340", "78861451031150840", "1770536585183202980", "41729280102868841080", "1030007496863617367420", "26568602827124392999640" ]
[ "nonn" ]
65
0
5
[ "A002720", "A002793", "A056952", "A073003", "A199577" ]
[ "M3567", "N1446" ]
N. J. A. Sloane, Robert G. Wilson v
2022-10-18T19:12:52
oeisdata/seq/A002/A002793.seq
4d1d8f2212fa6f7575b54909d62f0ad6
A002794
Numerators of convergents to Lehmer's constant.
[ "1", "1", "3", "16", "547", "538811", "620245817465", "692770666469127829226736", "1025344764595988314871439243086711931108916434521" ]
[ "nonn", "frac", "nice" ]
25
0
5
[ "A002065", "A002665", "A002794", "A002795", "A030125" ]
[ "M3034", "N1230" ]
N. J. A. Sloane
2024-10-13T01:26:54
oeisdata/seq/A002/A002794.seq
7097cb0480e7c6f4cbd81f5e795d8b6d
A002795
Denominators of convergents to Lehmer's constant.
[ "1", "2", "5", "27", "923", "909182", "1046593950039", "1168971346319460027570137", "1730152138254248421873938035305987364739567671241" ]
[ "nonn", "frac" ]
21
0
5
[ "A002065", "A002665", "A002794", "A002795", "A030125" ]
[ "M1545", "N0603" ]
N. J. A. Sloane
2024-10-13T01:27:18
oeisdata/seq/A002/A002795.seq
1be69e809d26f025dfbc839017559585
A002796
Numbers that are divisible by each nonzero digit.
[ "1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "15", "20", "22", "24", "30", "33", "36", "40", "44", "48", "50", "55", "60", "66", "70", "77", "80", "88", "90", "99", "100", "101", "102", "104", "105", "110", "111", "112", "115", "120", "122", "124", "126", "128", "132", "135", "140", "144", "150", "155", "162", "168", "175", "184", "200", "202", "204", "208", "210", "212" ]
[ "nonn", "base", "easy", "nice" ]
69
0
5
[ "A002796", "A007602", "A034838", "A067458", "A171492", "A237851" ]
[ "M0474", "N0175" ]
N. J. A. Sloane
2022-09-08T08:44:31
oeisdata/seq/A002/A002796.seq
a82106d2cdffec70b44d608a104ecadc
A002797
Number of solutions to a linear inequality.
[ "3", "2", "5", "9", "17", "27", "40", "55", "73", "94", "117", "143", "171", "203", "236", "273", "311", "354", "397", "445", "493", "547", "600", "659", "717", "782", "845", "915", "983", "1059", "1132", "1213", "1291", "1378", "1461", "1553", "1641", "1739", "1832", "1935", "2033", "2142", "2245", "2359", "2467", "2587", "2700" ]
[ "nonn", "easy" ]
27
0
5
null
[ "M1360", "N0524" ]
N. J. A. Sloane
2023-06-25T19:59:55
oeisdata/seq/A002/A002797.seq
54cd459f1268a014a665ecfa2d5630d4
A002798
a(n) = a(n-1) + a(n-2) - a(n-3).
[ "18", "45", "69", "96", "120", "147", "171", "198", "222", "249", "273", "300", "324", "351", "375", "402", "426", "453", "477", "504", "528", "555", "579", "606", "630", "657", "681", "708", "732", "759", "783", "810", "834", "861", "885", "912", "936", "963", "987", "1014", "1038", "1065", "1089" ]
[ "nonn" ]
49
0
5
[ "A002798", "A007310", "A047208" ]
[ "M5055", "N2186" ]
N. J. A. Sloane and Simon Plouffe
2025-04-02T04:13:26
oeisdata/seq/A002/A002798.seq
c509b743b4396c3fb3ae1ac3c99e6638
A002799
Number of 4-line partitions of n (i.e., planar partitions of n with at most 4 lines).
[ "1", "1", "3", "6", "13", "23", "45", "78", "141", "239", "409", "674", "1116", "1794", "2882", "4544", "7131", "11031", "16983", "25844", "39124", "58680", "87538", "129578", "190830", "279140", "406334", "588026", "847034", "1213764", "1731780", "2459244", "3478185", "4898285", "6872041", "9603356", "13372607", "18553871", "25656865" ]
[ "nonn" ]
62
0
5
[ "A000041", "A000219", "A000990", "A000991", "A001452", "A002799", "A225196", "A225197", "A225198", "A225199", "A242641" ]
[ "M2563", "N1014" ]
N. J. A. Sloane
2022-09-08T08:44:31
oeisdata/seq/A002/A002799.seq
efac9e22245e31ef2d83ac402df7dc47
A002800
Erroneous version of A001157.
[ "1", "5", "10", "21", "26", "53", "50", "85", "91", "130", "122", "210", "170", "250", "260", "341", "290", "455" ]
[ "dead" ]
13
0
5
null
[ "M3800", "N1552" ]
null
2014-05-21T18:02:12
oeisdata/seq/A002/A002800.seq
92cb9727c70756c778de119bab8397c5