Datasets:
christopher
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oeis

Dataset card Data Studio Files
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1999-12-11 03:00:00
2025-04-25 01:21:50
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32
32
A002401
Coefficients for step-by-step integration.
[ "1", "1", "5", "27", "502", "2375", "95435", "1287965", "29960476", "262426878", "28184365650", "303473091075", "46437880787562", "593196287807409", "8172332906336599", "241563260379065625", "64808657541894257992", "1087738506483388123364", "367580830209839294339148", "6906008426663826491899602", "136666305828261517346022452" ]
[ "nonn" ]
31
0
5
[ "A002397", "A002398", "A002399", "A002400", "A002401", "A002402", "A002403", "A002404", "A002405", "A002406", "A260780", "A260781" ]
[ "M3947", "N1626" ]
N. J. A. Sloane
2022-01-05T00:10:31
oeisdata/seq/A002/A002401.seq
70c550c96d2cb851a866dc127c511ac3
A002402
Coefficients for step-by-step integration.
[ "1", "8", "57", "1292", "7135", "325560", "4894715", "125078632", "1190664342", "137798986920", "1587893097945", "258558380321076", "3497709055775649", "50821738502398864", "1578753057237451095", "443765620067972169968", "7782162960545369351956", "2741163034641146307693072", "53564617257321061756508358", "1100369599246721484969558920" ]
[ "nonn" ]
23
0
5
[ "A002397", "A002398", "A002399", "A002400", "A002401", "A002402", "A002403", "A002404", "A002405", "A002406", "A260780", "A260781" ]
[ "M4547", "N1931" ]
N. J. A. Sloane
2023-10-16T23:20:52
oeisdata/seq/A002/A002402.seq
eb0f7bb69ed7ec7e400b17c6626c57c4
A002403
Coefficients for step-by-step integration.
[ "1", "15", "528", "3990", "232305", "4262895", "128928632", "1420184304", "186936865290", "2416826727315", "436683783190248", "6495589851083190", "102988034105173217", "3468347338313592735", "1050976389766688264880", "19771777981152440202960", "7439086137698489458667340", "154685313008524836907739370", "3369940174123349111629009120" ]
[ "nonn" ]
24
0
5
[ "A002397", "A002398", "A002399", "A002400", "A002401", "A002402", "A002403", "A002404", "A002405", "A002406", "A260780", "A260781" ]
[ "M4992", "N2148" ]
N. J. A. Sloane
2023-10-16T23:21:30
oeisdata/seq/A002/A002403.seq
20e20ea85cc196f54c744c7c94bf61a0
A002404
Coefficients for step-by-step integration.
[ "3", "-16", "111", "-2548", "14385", "-672360", "10351845", "-270594968", "2631486186", "-310710613080", "3648232023975", "-604596371658444", "8315244191734623", "-122717408718016112", "3868618892876082345", "-1102643727493413977872", "19593301788429800483052", "-6988461512994426036295152", "138198195880599649938536250" ]
[ "sign" ]
23
0
5
[ "A002397", "A002398", "A002399", "A002400", "A002401", "A002402", "A002403", "A002404", "A002405", "A002406", "A260780", "A260781" ]
[ "M3022", "N1224" ]
N. J. A. Sloane
2023-10-16T23:22:13
oeisdata/seq/A002/A002404.seq
aca8b049da48114637eb0d568bb7448b
A002405
Coefficients for step-by-step integration.
[ "1", "-1", "-1", "-3", "-38", "-135", "-4315", "-48125", "-950684", "-7217406", "-682590930", "-6554931075", "-903921420138", "-10496162430897", "-132415122967127", "-3606726811032345", "-896549281211592008", "-14008671728814262500", "-4425739007479443851340" ]
[ "sign" ]
43
0
5
[ "A002397", "A002398", "A002399", "A002400", "A002401", "A002402", "A002403", "A002404", "A002405", "A002406", "A260780", "A260781" ]
[ "M3145", "N1274" ]
N. J. A. Sloane
2021-10-03T22:18:56
oeisdata/seq/A002/A002405.seq
dd7582042f8c70ad3d3c178097791b7f
A002406
Coefficients for step-by-step integration.
[ "1", "8", "-15", "212", "-865", "31560", "-397285", "8760472", "-73512810", "7619823960", "-79612742055", "11869626289356", "-148201090063455", "2000757995572336", "-58073355854498985", "15325818191986269968", "-253388757170439526636", "84454267865884467099120", "-1566608640281391343515450", "30637801046762651850275960" ]
[ "sign" ]
24
0
5
[ "A002397", "A002398", "A002399", "A002400", "A002401", "A002402", "A002403", "A002404", "A002405", "A002406", "A260780", "A260781" ]
[ "M4486", "N1899" ]
N. J. A. Sloane
2023-10-16T23:22:53
oeisdata/seq/A002/A002406.seq
89a50eb690b54691f1c1b51d700625e8
A002407
Cuban primes: primes which are the difference of two consecutive cubes.
[ "7", "19", "37", "61", "127", "271", "331", "397", "547", "631", "919", "1657", "1801", "1951", "2269", "2437", "2791", "3169", "3571", "4219", "4447", "5167", "5419", "6211", "7057", "7351", "8269", "9241", "10267", "11719", "12097", "13267", "13669", "16651", "19441", "19927", "22447", "23497", "24571", "25117", "26227", "27361", "33391" ]
[ "nonn", "easy", "nice" ]
204
0
5
[ "A000217", "A002407", "A002504", "A002648", "A003215", "A003627", "A007645", "A111251", "A113478", "A145203", "A201477", "A334520" ]
[ "M4363", "N1828" ]
N. J. A. Sloane
2025-02-16T08:32:25
oeisdata/seq/A002/A002407.seq
64d24cb5c8ab254a1b8b6757d76a1f19
A002408
Expansion of 8-dimensional cusp form.
[ "0", "1", "-8", "28", "-64", "126", "-224", "344", "-512", "757", "-1008", "1332", "-1792", "2198", "-2752", "3528", "-4096", "4914", "-6056", "6860", "-8064", "9632", "-10656", "12168", "-14336", "15751", "-17584", "20440", "-22016", "24390", "-28224", "29792", "-32768", "37296", "-39312", "43344", "-48448", "50654", "-54880", "61544", "-64512", "68922" ]
[ "sign", "nice", "easy", "mult" ]
56
0
5
[ "A000122", "A000700", "A002408", "A007331", "A010054", "A045823", "A121373" ]
null
N. J. A. Sloane and Mira Bernstein
2025-02-16T08:32:25
oeisdata/seq/A002/A002408.seq
c5e162a6583bfddcd4ab9a5c7aa79ebb
A002409
a(n) = 2^n*C(n+6,6). Number of 6D hypercubes in an (n+6)-dimensional hypercube.
[ "1", "14", "112", "672", "3360", "14784", "59136", "219648", "768768", "2562560", "8200192", "25346048", "76038144", "222265344", "635043840", "1778122752", "4889837568", "13231325184", "35283533824", "92851404800", "241413652480", "620777963520", "1580162088960" ]
[ "nonn", "easy" ]
64
0
5
[ "A000079", "A001787", "A001788", "A001789", "A002409", "A003472", "A006976", "A038207", "A054849", "A054851", "A082140" ]
[ "M4939", "N1668" ]
N. J. A. Sloane
2022-09-08T08:44:30
oeisdata/seq/A002/A002409.seq
21afe74b5585886743e407b84650c6ae
A002410
Nearest integer to imaginary part of n-th zero of Riemann zeta function.
[ "14", "21", "25", "30", "33", "38", "41", "43", "48", "50", "53", "56", "59", "61", "65", "67", "70", "72", "76", "77", "79", "83", "85", "87", "89", "92", "95", "96", "99", "101", "104", "105", "107", "111", "112", "114", "116", "119", "121", "123", "124", "128", "130", "131", "133", "135", "138", "140", "141", "143", "146", "147", "150", "151", "153", "156", "158", "159", "161" ]
[ "nonn", "easy", "nice" ]
320
0
5
[ "A002410", "A013629", "A057640", "A057641", "A058209", "A058210", "A058303", "A065434", "A065452", "A065453", "A072080", "A092783", "A120401", "A122526", "A124288", "A124289", "A177885", "A192492", "A236212", "A305741", "A305742", "A305743", "A305744", "A306004", "A374074" ]
[ "M4924", "N2113" ]
N. J. A. Sloane
2025-02-16T08:32:25
oeisdata/seq/A002/A002410.seq
ff27a689f59cd828c1de4d10a5a370f1
A002411
Pentagonal pyramidal numbers: a(n) = n^2*(n+1)/2.
[ "0", "1", "6", "18", "40", "75", "126", "196", "288", "405", "550", "726", "936", "1183", "1470", "1800", "2176", "2601", "3078", "3610", "4200", "4851", "5566", "6348", "7200", "8125", "9126", "10206", "11368", "12615", "13950", "15376", "16896", "18513", "20230", "22050", "23976", "26011", "28158", "30420", "32800", "35301", "37926", "40678" ]
[ "nonn", "easy", "nice" ]
312
0
5
[ "A001296", "A002411", "A006002", "A011379", "A014799", "A014800", "A015223", "A015224", "A093560", "A103371", "A127739", "A132118", "A132191", "A139600", "A237616" ]
[ "M4116", "N1709" ]
N. J. A. Sloane
2025-02-16T08:32:25
oeisdata/seq/A002/A002411.seq
412eb16b39f065bddd330de1eeae77cb
A002412
Hexagonal pyramidal numbers, or greengrocer's numbers.
[ "0", "1", "7", "22", "50", "95", "161", "252", "372", "525", "715", "946", "1222", "1547", "1925", "2360", "2856", "3417", "4047", "4750", "5530", "6391", "7337", "8372", "9500", "10725", "12051", "13482", "15022", "16675", "18445", "20336", "22352", "24497", "26775", "29190", "31746", "34447", "37297", "40300" ]
[ "nonn", "easy", "nice" ]
180
0
5
[ "A000217", "A000292", "A000330", "A000578", "A000579", "A001477", "A002412", "A002623", "A005843", "A008585", "A016061", "A045943", "A093561", "A102860", "A115067", "A154286", "A220084", "A237616" ]
[ "M4374", "N1839" ]
N. J. A. Sloane
2025-02-16T08:32:25
oeisdata/seq/A002/A002412.seq
f8f0d2b9f3b6dcbe19436a9b495f1b5d
A002413
Heptagonal (or 7-gonal) pyramidal numbers: a(n) = n*(n+1)*(5*n-2)/6.
[ "0", "1", "8", "26", "60", "115", "196", "308", "456", "645", "880", "1166", "1508", "1911", "2380", "2920", "3536", "4233", "5016", "5890", "6860", "7931", "9108", "10396", "11800", "13325", "14976", "16758", "18676", "20735", "22940", "25296", "27808", "30481", "33320", "36330", "39516", "42883", "46436", "50180", "54120" ]
[ "nonn", "easy", "nice" ]
98
0
5
[ "A002413", "A093562", "A237616" ]
[ "M4498", "N1904" ]
N. J. A. Sloane
2025-02-16T08:32:25
oeisdata/seq/A002/A002413.seq
90ffb4dbb498b4340392aaba770647f6
A002414
Octagonal pyramidal numbers: a(n) = n*(n+1)*(2*n-1)/2.
[ "1", "9", "30", "70", "135", "231", "364", "540", "765", "1045", "1386", "1794", "2275", "2835", "3480", "4216", "5049", "5985", "7030", "8190", "9471", "10879", "12420", "14100", "15925", "17901", "20034", "22330", "24795", "27435", "30256", "33264", "36465", "39865", "43470", "47286", "51319", "55575", "60060", "64780" ]
[ "nonn", "easy", "nice" ]
161
0
5
[ "A000326", "A000567", "A000578", "A002414", "A004003", "A093563", "A156927", "A157704", "A160378", "A237616", "A260234" ]
[ "M4609", "N1966" ]
N. J. A. Sloane
2024-07-26T21:16:31
oeisdata/seq/A002/A002414.seq
465e34d68db353aca8c46bde31b71d1f
A002415
4-dimensional pyramidal numbers: a(n) = n^2*(n^2-1)/12.
[ "0", "0", "1", "6", "20", "50", "105", "196", "336", "540", "825", "1210", "1716", "2366", "3185", "4200", "5440", "6936", "8721", "10830", "13300", "16170", "19481", "23276", "27600", "32500", "38025", "44226", "51156", "58870", "67425", "76880", "87296", "98736", "111265", "124950", "139860", "156066", "173641", "192660", "213200", "235340" ]
[ "nonn", "easy", "nice" ]
346
0
5
[ "A000012", "A000027", "A000217", "A000330", "A001079", "A001263", "A001296", "A002388", "A002415", "A006011", "A006542", "A006857", "A008911", "A024206", "A037270", "A047819", "A047928", "A051602", "A053120", "A071253", "A083374", "A103905", "A107891", "A108279", "A108679", "A108741", "A114327", "A132592", "A134288", "A134289", "A134290", "A134291", "A140925", "A140935", "A146311", "A146312", "A146313", "A169937", "A173115", "A173116", "A220212" ]
[ "M4135", "N1714" ]
N. J. A. Sloane
2025-03-05T10:42:44
oeisdata/seq/A002/A002415.seq
19fb99c130c4fde1723c311f6b6e7ee0
A002416
a(n) = 2^(n^2).
[ "1", "2", "16", "512", "65536", "33554432", "68719476736", "562949953421312", "18446744073709551616", "2417851639229258349412352", "1267650600228229401496703205376", "2658455991569831745807614120560689152", "22300745198530623141535718272648361505980416", "748288838313422294120286634350736906063837462003712" ]
[ "nonn", "easy" ]
117
0
5
[ "A002416", "A053763", "A060656", "A064062", "A064231", "A319015" ]
null
N. J. A. Sloane
2025-02-16T08:32:25
oeisdata/seq/A002/A002416.seq
5064cb7237b99d7c9917b4af1f88df61
A002417
4-dimensional figurate numbers: a(n) = n*binomial(n+2, 3).
[ "1", "8", "30", "80", "175", "336", "588", "960", "1485", "2200", "3146", "4368", "5915", "7840", "10200", "13056", "16473", "20520", "25270", "30800", "37191", "44528", "52900", "62400", "73125", "85176", "98658", "113680", "130355", "148800", "169136", "191488", "215985", "242760", "271950", "303696", "338143", "375440", "415740" ]
[ "nonn", "easy", "nice" ]
147
0
5
[ "A000027", "A000332", "A000384", "A002412", "A002417", "A002624", "A062196", "A093561", "A151974", "A213750", "A220212", "A290939", "A290940" ]
[ "M4506", "N1907" ]
N. J. A. Sloane
2025-02-16T08:32:25
oeisdata/seq/A002/A002417.seq
17d006d1300c612522ac665186afeda5
A002418
4-dimensional figurate numbers: a(n) = (5*n-1)*binomial(n+2,3)/4.
[ "0", "1", "9", "35", "95", "210", "406", "714", "1170", "1815", "2695", "3861", "5369", "7280", "9660", "12580", "16116", "20349", "25365", "31255", "38115", "46046", "55154", "65550", "77350", "90675", "105651", "122409", "141085", "161820", "184760", "210056", "237864", "268345", "301665", "337995" ]
[ "nonn", "easy" ]
95
0
5
[ "A000332", "A000566", "A001622", "A002418", "A080852", "A093562", "A128064", "A220212" ]
[ "M4617", "N1970" ]
N. J. A. Sloane
2024-07-31T09:06:50
oeisdata/seq/A002/A002418.seq
d8780342f66408013189f1c9f0183c31
A002419
4-dimensional figurate numbers: a(n) = (6*n-2)*binomial(n+2,3)/4.
[ "1", "10", "40", "110", "245", "476", "840", "1380", "2145", "3190", "4576", "6370", "8645", "11480", "14960", "19176", "24225", "30210", "37240", "45430", "54901", "65780", "78200", "92300", "108225", "126126", "146160", "168490", "193285", "220720", "250976", "284240", "320705", "360570", "404040", "451326", "502645", "558220" ]
[ "nonn", "easy" ]
86
0
5
[ "A000027", "A000567", "A002414", "A002419", "A016777", "A080852", "A093563", "A213761", "A220212" ]
[ "M4699", "N2008" ]
N. J. A. Sloane
2025-02-16T08:32:25
oeisdata/seq/A002/A002419.seq
27ddbe905a980ca3427be7ecf1c2bccb
A002420
Expansion of sqrt(1 - 4*x) in powers of x.
[ "1", "-2", "-2", "-4", "-10", "-28", "-84", "-264", "-858", "-2860", "-9724", "-33592", "-117572", "-416024", "-1485800", "-5348880", "-19389690", "-70715340", "-259289580", "-955277400", "-3534526380", "-13128240840", "-48932534040", "-182965127280", "-686119227300", "-2579808294648", "-9723892802904", "-36734706144304" ]
[ "sign", "nice", "easy" ]
122
0
5
[ "A000108", "A000984", "A001622", "A002420", "A068875", "A262543" ]
[ "M0337", "N0128" ]
N. J. A. Sloane, Dec 11 1996
2025-02-28T06:22:39
oeisdata/seq/A002/A002420.seq
c753b2882b370da9485b6e8884efbb6c
A002421
Expansion of (1-4*x)^(3/2) in powers of x.
[ "1", "-6", "6", "4", "6", "12", "28", "72", "198", "572", "1716", "5304", "16796", "54264", "178296", "594320", "2005830", "6843420", "23571780", "81880920", "286583220", "1009864680", "3580429320", "12765008880", "45741281820", "164668614552", "595340375688", "2160865067312", "7871722745208", "28772503827312" ]
[ "sign", "easy" ]
103
0
5
[ "A000257", "A001622", "A002420", "A002421", "A002422", "A002423", "A002424", "A004001", "A007054", "A071721", "A071724", "A085687" ]
[ "M4058", "N1683" ]
N. J. A. Sloane
2025-01-11T09:07:03
oeisdata/seq/A002/A002421.seq
b6f6afc1d079adf6a34bce3483d16429
A002422
Expansion of (1-4*x)^(5/2).
[ "1", "-10", "30", "-20", "-10", "-12", "-20", "-40", "-90", "-220", "-572", "-1560", "-4420", "-12920", "-38760", "-118864", "-371450", "-1179900", "-3801900", "-12406200", "-40940460", "-136468200", "-459029400", "-1556708400", "-5318753700", "-18296512728", "-63334082520" ]
[ "sign" ]
51
0
5
[ "A001622", "A002420", "A002421", "A002422", "A002423", "A002424", "A004001", "A007054", "A007272" ]
[ "M4692", "N2003" ]
N. J. A. Sloane
2022-03-24T08:05:04
oeisdata/seq/A002/A002422.seq
aae854ffa58107d63711a74d89fbe050
A002423
Expansion of (1-4*x)^(7/2).
[ "1", "-14", "70", "-140", "70", "28", "28", "40", "70", "140", "308", "728", "1820", "4760", "12920", "36176", "104006", "305900", "917700", "2801400", "8684340", "27293640", "86843400", "279409200", "908079900", "2978502072", "9851968392", "32839894640" ]
[ "sign", "easy", "nice" ]
51
0
5
[ "A001622", "A002420", "A002421", "A002422", "A002423", "A002424", "A004001", "A007054", "A007272" ]
[ "M4934", "N2114" ]
N. J. A. Sloane
2022-03-24T08:05:10
oeisdata/seq/A002/A002423.seq
8d95b9e9efc05084628c0296e9a3e076
A002424
Expansion of (1-4*x)^(9/2).
[ "1", "-18", "126", "-420", "630", "-252", "-84", "-72", "-90", "-140", "-252", "-504", "-1092", "-2520", "-6120", "-15504", "-40698", "-110124", "-305900", "-869400", "-2521260", "-7443720", "-22331160", "-67964400", "-209556900", "-653817528", "-2062039896", "-6567978928", "-21111360840" ]
[ "sign", "easy", "nice" ]
47
0
5
[ "A001622", "A002420", "A002421", "A002422", "A002423", "A002424", "A004001", "A007054", "A007272" ]
[ "M5058", "N2188" ]
N. J. A. Sloane
2022-03-25T05:14:40
oeisdata/seq/A002/A002424.seq
7c27045b4ca90aee092f28a82ba79d08
A002425
Denominator of Pi^(2n)/(Gamma(2n)*(1-2^(-2n))*zeta(2n)).
[ "1", "1", "1", "17", "31", "691", "5461", "929569", "3202291", "221930581", "4722116521", "968383680827", "14717667114151", "2093660879252671", "86125672563201181", "129848163681107301953", "868320396104950823611", "209390615747646519456961" ]
[ "nonn", "frac", "easy" ]
104
0
5
[ "A002425", "A037239", "A048896", "A089170", "A089171", "A160469", "A275994", "A335956" ]
[ "M5036", "N2174" ]
N. J. A. Sloane
2022-08-26T02:49:09
oeisdata/seq/A002/A002425.seq
6b3b965b8f4d85cbb66263d1b63a6395
A002426
Central trinomial coefficients: largest coefficient of (1 + x + x^2)^n.
[ "1", "1", "3", "7", "19", "51", "141", "393", "1107", "3139", "8953", "25653", "73789", "212941", "616227", "1787607", "5196627", "15134931", "44152809", "128996853", "377379369", "1105350729", "3241135527", "9513228123", "27948336381", "82176836301", "241813226151", "712070156203", "2098240353907", "6186675630819" ]
[ "nonn", "nice", "core", "easy", "changed" ]
550
0
5
[ "A001006", "A002426", "A002878", "A005043", "A005717", "A007971", "A027907", "A082758", "A097893", "A102445", "A113302", "A113303", "A113304", "A113305", "A152227", "A168597", "A201552", "A273055", "A277640", "A305161", "A328347" ]
[ "M2673", "N1070" ]
N. J. A. Sloane, Simon Plouffe
2025-04-23T10:46:42
oeisdata/seq/A002/A002426.seq
63ec2a89e3109d6263373fb123e4ffdb
A002427
Numerator of (2n+1) B_{2n}, where B_n are the Bernoulli numbers.
[ "1", "1", "-1", "1", "-3", "5", "-691", "35", "-3617", "43867", "-1222277", "854513", "-1181820455", "76977927", "-23749461029", "8615841276005", "-84802531453387", "90219075042845", "-26315271553053477373", "38089920879940267", "-261082718496449122051", "1520097643918070802691" ]
[ "sign", "easy", "nice", "frac" ]
44
0
5
[ "A000367", "A002427", "A002445", "A006955", "A050925", "A050932" ]
[ "M2510", "N0993" ]
N. J. A. Sloane
2022-11-29T04:45:11
oeisdata/seq/A002/A002427.seq
2cf917bd5184277b7c909b4c0103c3da
A002428
Numerators of coefficients of expansion of arctan(x)^2 = x^2 - 2/3*x^4 + 23/45*x^6 - 44/105*x^8 + 563/1575*x^10 - 3254/10395*x^12 + ...
[ "0", "1", "-2", "23", "-44", "563", "-3254", "88069", "-11384", "1593269", "-15518938", "31730711", "-186088972", "3788707301", "-5776016314", "340028535787", "-667903294192", "10823198495797", "-5476065119726", "409741429887649", "-103505656241356", "17141894231615609" ]
[ "sign", "easy", "frac" ]
45
0
5
[ "A002428", "A002549", "A004041", "A025550", "A035048", "A071968" ]
[ "M2131", "N0844" ]
N. J. A. Sloane
2022-02-27T15:51:57
oeisdata/seq/A002/A002428.seq
749c413691124fb4e55733c39ae16474
A002429
Numerators of double sums of reciprocals.
[ "1", "1", "14", "818", "141", "13063", "16774564", "1057052", "4651811", "778001383", "1947352646", "1073136102266", "72379420806883", "112229882767", "120372921248744", "13224581478608216", "2077531074698521033", "517938126297258811", "13785854249175914469406", "343586489824688536178", "1958290344469311726833" ]
[ "nonn" ]
36
0
5
[ "A002429", "A008309", "A049218" ]
[ "M4956", "N2124" ]
N. J. A. Sloane
2022-09-08T08:44:30
oeisdata/seq/A002/A002429.seq
7785a91bc3254bff09c33a764e7c76c1
A002430
Numerators in Taylor series for tan(x). Also from Taylor series for tanh(x).
[ "1", "1", "2", "17", "62", "1382", "21844", "929569", "6404582", "443861162", "18888466084", "113927491862", "58870668456604", "8374643517010684", "689005380505609448", "129848163681107301953", "1736640792209901647222", "418781231495293038913922" ]
[ "nonn", "easy", "frac" ]
64
0
5
[ "A000182", "A002430", "A036279", "A099612", "A156769", "A160469" ]
[ "M2100", "N0832" ]
N. J. A. Sloane
2025-02-16T08:32:25
oeisdata/seq/A002/A002430.seq
fc076da74f8eeb295b85f7615f80ae86
A002431
Numerators in Taylor series for cot x.
[ "1", "-1", "-1", "-2", "-1", "-2", "-1382", "-4", "-3617", "-87734", "-349222", "-310732", "-472728182", "-2631724", "-13571120588", "-13785346041608", "-7709321041217", "-303257395102", "-52630543106106954746", "-616840823966644", "-522165436992898244102", "-6080390575672283210764", "-10121188937927645176372" ]
[ "sign", "frac", "easy", "nice" ]
74
0
5
[ "A000182", "A002431", "A036278" ]
[ "M0124", "N0050" ]
N. J. A. Sloane
2025-02-16T08:32:25
oeisdata/seq/A002/A002431.seq
258e48f7c7ff0fd079a22ed1c0142e74
A002432
Denominators of zeta(2*n)/Pi^(2*n).
[ "2", "6", "90", "945", "9450", "93555", "638512875", "18243225", "325641566250", "38979295480125", "1531329465290625", "13447856940643125", "201919571963756521875", "11094481976030578125", "564653660170076273671875", "5660878804669082674070015625", "62490220571022341207266406250" ]
[ "nonn", "nice", "easy", "frac" ]
176
0
5
[ "A002432", "A006003", "A046988" ]
[ "M4283", "N1790" ]
N. J. A. Sloane
2025-02-16T08:32:25
oeisdata/seq/A002/A002432.seq
48d34dd68b9995353e7b296ad58c5fb6
A002433
Theta series of unique 26-dimensional unimodular lattice T_26 with no roots (and minimal norm 3).
[ "1", "0", "0", "3120", "102180", "1482624", "13191360", "83859360", "416587860", "1712638720", "6061945344", "19019791440", "54048571200", "141266958720", "343675612800", "786321725280", "1706284712340", "3532676509440", "7012626150400", "13413721342320", "24829712546184", "44601384921600" ]
[ "nonn" ]
16
0
5
null
null
N. J. A. Sloane
2023-10-16T23:24:03
oeisdata/seq/A002/A002433.seq
24ab0a12a70d7250afc1b82fc6eb3700
A002434
Theta series of Borcherds' 27-dimensional unimodular lattice T_27.
[ "1", "0", "0", "1640", "119574", "1497600", "16733184", "108081792", "588805308", "2544826368", "9516533760", "31328289720", "92876121704", "252846217728", "638250227712", "1511780699520", "3387237774102", "7228330481664" ]
[ "nonn" ]
20
0
5
null
null
N. J. A. Sloane
2020-08-14T03:43:50
oeisdata/seq/A002/A002434.seq
3a04797f721f192fbef164810b27d3af
A002435
Second-order Euler numbers.
[ "0", "2", "6", "28", "180", "662", "7266", "24568", "408360", "1326122", "30974526", "98329108", "3065784540", "9596075582", "384653685786", "1192744081648", "59724464976720", "183983154281042", "11249503075325046", "34489251602450188" ]
[ "nonn", "easy" ]
20
0
5
null
[ "M1686", "N0665" ]
N. J. A. Sloane
2014-04-18T05:56:04
oeisdata/seq/A002/A002435.seq
e09bfce6bbe936b664e4816a67ddc6e7
A002436
E.g.f.: Sum_{n >= 0} a(n)*x^(2*n)/(2*n)! = sec(2*x).
[ "1", "4", "80", "3904", "354560", "51733504", "11070525440", "3266330312704", "1270842139934720", "630424777638805504", "388362339077351014400", "290870261262635870715904", "260290690801376575335956480", "274278793184290987427604987904", "336150887870579862992197737512960" ]
[ "nonn", "easy", "nice", "changed" ]
92
0
5
[ "A000364", "A000816", "A000831", "A002436", "A060187" ]
[ "M3701", "N1512" ]
N. J. A. Sloane
2025-04-15T08:27:38
oeisdata/seq/A002/A002436.seq
f319311c9cc40e478b5a722b944e09d0
A002437
a(n) = A000364(n) * (3^(2*n+1) + 1)/4.
[ "1", "7", "305", "33367", "6815585", "2237423527", "1077270776465", "715153093789687", "626055764653322945", "698774745485355051847", "968553361387420436695025", "1632180870878422847476890007", "3286322019402928956112227932705", "7791592461957309952817483706344167", "21485762937086358457367440231243675985" ]
[ "nonn", "easy" ]
52
0
5
[ "A000191", "A000281", "A000364", "A001209", "A002437", "A012494", "A156134", "A156168", "A156169", "A349429" ]
[ "M4462", "N1891" ]
N. J. A. Sloane
2022-04-21T13:53:03
oeisdata/seq/A002/A002437.seq
f8214789acceaa239e2ac0f9175be6cf
A002438
Multiples of Euler numbers.
[ "1", "5", "205", "22265", "4544185", "1491632525", "718181418565", "476768795646785", "417370516232719345", "465849831125196593045", "645702241048404020542525", "1088120580608731523115639305", "2190881346273790815462670984105" ]
[ "nonn", "easy", "nice" ]
47
0
5
[ "A000364", "A002438", "A086646", "A255884" ]
[ "M4029", "N1672" ]
N. J. A. Sloane
2017-12-04T17:46:39
oeisdata/seq/A002/A002438.seq
11acf3fd3c525b969594d8dfd7c4278a
A002439
Glaisher's T numbers.
[ "1", "23", "1681", "257543", "67637281", "27138236663", "15442193173681", "11828536957233383", "11735529528739490881", "14639678925928297567703", "22427641105413135505628881", "41393949926819051111431239623", "90592214447886493688036507587681", "231969423543894989257690172433129143" ]
[ "nonn", "easy", "nice", "changed" ]
116
0
5
[ "A000191", "A000364", "A000464", "A002105", "A002439", "A079144", "A156175", "A156176", "A158690", "A208679", "A208680", "A208681" ]
[ "M5138", "N2228" ]
N. J. A. Sloane
2025-04-17T03:36:31
oeisdata/seq/A002/A002439.seq
daa457e44aa40696ea35fee7b1bfc1d6
A002440
Squares written in base 7.
[ "1", "4", "12", "22", "34", "51", "100", "121", "144", "202", "232", "264", "331", "400", "441", "514", "562", "642", "1024", "1111", "1200", "1261", "1354", "1452", "1552", "1654", "2061", "2200", "2311", "2424", "2542", "2662", "3114", "3241", "3400", "3531", "3664", "4132", "4302", "4444", "4621", "5100", "5251", "5434", "5622", "6112", "6304" ]
[ "nonn", "base", "easy" ]
22
0
5
null
[ "M3431", "N1392" ]
N. J. A. Sloane
2023-10-16T23:25:20
oeisdata/seq/A002/A002440.seq
b16f704eba4424d041ce091c35fd58ca
A002441
Squares written in base 8.
[ "1", "4", "11", "20", "31", "44", "61", "100", "121", "144", "171", "220", "251", "304", "341", "400", "441", "504", "551", "620", "671", "744", "1021", "1100", "1161", "1244", "1331", "1420", "1511", "1604", "1701", "2000", "2101", "2204", "2311", "2420", "2531", "2644", "2761", "3100", "3221", "3344", "3471", "3620", "3751", "4104", "4241" ]
[ "nonn", "easy", "base" ]
29
0
5
[ "A000290", "A002441", "A007094" ]
[ "M3408", "N1378" ]
N. J. A. Sloane
2022-09-08T08:44:30
oeisdata/seq/A002/A002441.seq
fd8aafa67f79e228f16a494e23baf15a
A002442
Squares written in base 9.
[ "1", "4", "10", "17", "27", "40", "54", "71", "100", "121", "144", "170", "207", "237", "270", "314", "351", "400", "441", "484", "540", "587", "647", "710", "764", "831", "1000", "1061", "1134", "1210", "1277", "1357", "1440", "1524", "1611", "1700", "1781", "1874", "2070", "2167", "2267", "2370", "2474", "2581", "2700", "2811", "3024", "3140", "3257" ]
[ "nonn", "base", "easy" ]
32
0
5
[ "A000290", "A002442", "A007095" ]
[ "M3377", "N1361" ]
N. J. A. Sloane
2023-04-22T14:04:14
oeisdata/seq/A002/A002442.seq
55db2aef65144ee04f56686514ece5bf
A002443
Numerator in Feinler's formula for unsigned Bernoulli number |B_{2n}|.
[ "1", "1", "1", "2", "3", "10", "1382", "420", "10851", "438670", "7333662", "51270780", "7090922730", "2155381956", "94997844116", "68926730208040", "1780853160521127", "541314450257070", "52630543106106954746", "15997766769574912140", "10965474176850863126142", "1003264444985926729776060", "35069919669919290536128980" ]
[ "nonn", "frac" ]
37
0
5
[ "A000367", "A002443", "A002444", "A002445", "A266742", "A266743", "A266911" ]
[ "M0906", "N0341" ]
N. J. A. Sloane
2016-01-08T21:01:05
oeisdata/seq/A002/A002443.seq
0f0c6e80584ff68e25395d7b876b9472
A002444
Denominator in Feinler's formula for unsigned Bernoulli number |B_{2n}|.
[ "1", "6", "30", "84", "90", "132", "5460", "360", "1530", "7980", "13860", "8280", "81900", "1512", "3480", "114576", "117810", "1260", "3838380", "32760", "568260", "1191960", "869400", "236880", "9746100", "525096", "629640", "351120", "198360", "42480", "1362881520", "4324320", "1093950", "33008220", "434700", "843480", "46233287100", "102702600", "1081080" ]
[ "nonn", "frac" ]
48
0
5
[ "A000367", "A002443", "A002444", "A002445", "A266742", "A266743", "A266911" ]
[ "M4191", "N1747" ]
N. J. A. Sloane
2023-03-08T03:41:07
oeisdata/seq/A002/A002444.seq
2ebc5efac3fa06a26a81f77d067b3250
A002445
Denominators of Bernoulli numbers B_{2n}.
[ "1", "6", "30", "42", "30", "66", "2730", "6", "510", "798", "330", "138", "2730", "6", "870", "14322", "510", "6", "1919190", "6", "13530", "1806", "690", "282", "46410", "66", "1590", "798", "870", "354", "56786730", "6", "510", "64722", "30", "4686", "140100870", "6", "30", "3318", "230010", "498", "3404310", "6", "61410", "272118", "1410", "6", "4501770", "6", "33330", "4326", "1590", "642", "209191710", "1518", "1671270", "42" ]
[ "nonn", "frac", "nice" ]
147
0
5
[ "A000367", "A001897", "A002445", "A002882", "A003245", "A027641", "A027642", "A027762", "A028246", "A080092", "A090801", "A127187", "A127188", "A138239", "A143343", "A160014", "A277087" ]
[ "M4189", "N1746" ]
N. J. A. Sloane
2024-12-27T08:45:53
oeisdata/seq/A002/A002445.seq
81d87137056fb3c2b5e27f601c68e633
A002446
a(n) = 2^(2*n+1) - 2.
[ "0", "6", "30", "126", "510", "2046", "8190", "32766", "131070", "524286", "2097150", "8388606", "33554430", "134217726", "536870910", "2147483646", "8589934590", "34359738366", "137438953470", "549755813886", "2199023255550", "8796093022206", "35184372088830" ]
[ "nonn", "easy" ]
53
0
5
[ "A002446", "A002450", "A241171" ]
[ "M4193", "N1748" ]
N. J. A. Sloane
2022-09-08T08:44:30
oeisdata/seq/A002/A002446.seq
02c7f7a67093ac3746798b79957f0948
A002447
Expansion of 1/(1-2*x^2-3*x^3).
[ "1", "0", "2", "3", "4", "12", "17", "36", "70", "123", "248", "456", "865", "1656", "3098", "5907", "11164", "21108", "40049", "75708", "143422", "271563", "513968", "973392", "1842625", "3488688", "6605426", "12505251", "23676916", "44826780", "84869585", "160684308" ]
[ "nonn", "easy" ]
23
0
5
null
null
N. J. A. Sloane
2022-09-08T08:44:30
oeisdata/seq/A002/A002447.seq
906a721f72f4b5c562e5b722da18f607
A002448
Expansion of Jacobi theta function theta_4(x).
[ "1", "-2", "0", "0", "2", "0", "0", "0", "0", "-2", "0", "0", "0", "0", "0", "0", "2", "0", "0", "0", "0", "0", "0", "0", "0", "-2", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "2", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "-2", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "2", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "-2", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "2", "0", "0", "0", "0" ]
[ "sign", "easy" ]
77
0
5
[ "A000122", "A000203", "A002448", "A010054", "A089802" ]
null
N. J. A. Sloane
2025-02-16T08:32:25
oeisdata/seq/A002/A002448.seq
94110aa47a804665a812672c18976951
A002449
Number of different types of binary trees of height n.
[ "1", "1", "2", "6", "26", "166", "1626", "25510", "664666", "29559718", "2290267226", "314039061414", "77160820913242", "34317392762489766", "27859502236825957466", "41575811106337540656038", "114746581654195790543205466", "588765612737696531880325270438", "5642056933026209681424588087899226" ]
[ "nonn", "nice", "easy" ]
71
0
5
[ "A001699", "A002449", "A018819", "A056207", "A098539" ]
[ "M1683", "N0664" ]
N. J. A. Sloane
2024-12-10T12:29:40
oeisdata/seq/A002/A002449.seq
d9c1b98891f094a9947dbe13fce408b2
A002450
a(n) = (4^n - 1)/3.
[ "0", "1", "5", "21", "85", "341", "1365", "5461", "21845", "87381", "349525", "1398101", "5592405", "22369621", "89478485", "357913941", "1431655765", "5726623061", "22906492245", "91625968981", "366503875925", "1466015503701", "5864062014805", "23456248059221", "93824992236885", "375299968947541" ]
[ "nonn", "easy", "nice" ]
578
0
5
[ "A000225", "A000302", "A002446", "A002450", "A003714", "A006995", "A007583", "A018215", "A020988", "A024036", "A047849", "A048716", "A080355", "A080674", "A094028", "A112627", "A113860", "A129735", "A139391", "A155701", "A156605", "A160967", "A163834", "A163868", "A178415", "A263132", "A281379", "A347834" ]
[ "M3914", "N1608" ]
N. J. A. Sloane
2025-04-09T11:20:40
oeisdata/seq/A002/A002450.seq
574e9c87abac80a213be5c8591eaebd4
A002451
Expansion of 1/((1-x)*(1-4*x)*(1-9*x)).
[ "1", "14", "147", "1408", "13013", "118482", "1071799", "9668036", "87099705", "784246870", "7059619931", "63542171784", "571901915677", "5147206719578", "46325218390143", "416928397167052", "3752361301126529", "33771274616631006", "303941563175648035", "2735474435084708240", "24619271381777877861" ]
[ "nonn", "easy" ]
57
0
5
[ "A002451", "A036969" ]
[ "M4945", "N2118" ]
N. J. A. Sloane
2022-09-08T08:44:30
oeisdata/seq/A002/A002451.seq
cbf564aafa5bbad3d5ae526c89fc13e5
A002452
a(n) = (9^n - 1)/8.
[ "0", "1", "10", "91", "820", "7381", "66430", "597871", "5380840", "48427561", "435848050", "3922632451", "35303692060", "317733228541", "2859599056870", "25736391511831", "231627523606480", "2084647712458321", "18761829412124890", "168856464709124011", "1519708182382116100", "13677373641439044901", "123096362772951404110" ]
[ "nonn", "easy" ]
178
0
5
[ "A000217", "A002452", "A008958", "A011540", "A052382", "A125134", "A125857", "A217094" ]
[ "M4733", "N2025" ]
N. J. A. Sloane
2025-03-14T15:04:57
oeisdata/seq/A002/A002452.seq
ca61180f8283620ad9ce73149655e010
A002453
Central factorial numbers: 2nd subdiagonal of A008958.
[ "1", "35", "966", "24970", "631631", "15857205", "397027996", "9931080740", "248325446061", "6208571999575", "155218222621826", "3880490869237710", "97012589464171291", "2425317596203339145", "60632965641474990456", "1515824372664398367880" ]
[ "nonn", "easy" ]
81
0
5
[ "A002452", "A002453", "A008958" ]
[ "M5249", "N2283" ]
N. J. A. Sloane, Simon Plouffe
2025-01-13T10:51:11
oeisdata/seq/A002/A002453.seq
78b5bd81f60554d13c1622f9e39d7fcb
A002454
Central factorial numbers: a(n) = 4^n (n!)^2.
[ "1", "4", "64", "2304", "147456", "14745600", "2123366400", "416179814400", "106542032486400", "34519618525593600", "13807847410237440000", "6682998146554920960000", "3849406932415634472960000", "2602199086312968903720960000", "2040124083669367620517232640000" ]
[ "nonn", "easy" ]
104
0
5
[ "A000165", "A001818", "A002454", "A002474", "A002506", "A014401", "A079484", "A197036", "A334380", "J1", "J2", "J3" ]
[ "M3693", "N1510" ]
N. J. A. Sloane
2025-01-05T09:40:26
oeisdata/seq/A002/A002454.seq
8917bc14b5ccd9089ccb94844f43ef76
A002455
Central factorial numbers: unsigned 1st subdiagonal of A182867.
[ "0", "1", "20", "784", "52480", "5395456", "791691264", "157294854144", "40683662475264", "13288048674471936", "5349739088314368000", "2603081566154391552000", "1506057980251484454912000", "1021944601582419125993472000" ]
[ "nonn", "easy", "nice" ]
41
0
5
[ "A001819", "A001824", "A001825", "A002455", "A049033" ]
[ "M5103", "N2210" ]
N. J. A. Sloane
2025-01-20T06:42:53
oeisdata/seq/A002/A002455.seq
151407df806e664b8c24aab843329575
A002456
Joffe's central differences of 0, A241171(n,n-1).
[ "0", "1", "30", "1260", "75600", "6237000", "681080400", "95351256000", "16672848192000", "3563821301040000", "914714133933600000", "277707211062240960000", "98459829376612704000000", "40319300129722902288000000", "18888041368462498071840000000", "10037644841525784689606400000000" ]
[ "nonn" ]
26
0
5
[ "A002456", "A241171" ]
[ "M5216", "N2270" ]
N. J. A. Sloane
2023-10-16T23:26:40
oeisdata/seq/A002/A002456.seq
d11c23b774bd534dbdcaee4f0ab5ca75
A002457
a(n) = (2n+1)!/n!^2.
[ "1", "6", "30", "140", "630", "2772", "12012", "51480", "218790", "923780", "3879876", "16224936", "67603900", "280816200", "1163381400", "4808643120", "19835652870", "81676217700", "335780006100", "1378465288200", "5651707681620", "23145088600920", "94684453367400", "386971244197200", "1580132580471900" ]
[ "nonn", "easy", "nice", "changed" ]
359
0
5
[ "A000108", "A000217", "A000531", "A000984", "A001803", "A002457", "A033876", "A046521", "A132818", "A331430", "A331431" ]
[ "M4198", "N1752" ]
N. J. A. Sloane
2025-04-24T02:13:41
oeisdata/seq/A002/A002457.seq
626234ee5d975b763d5d8945ea53620d
A002458
a(n) = binomial(4*n+1, 2*n).
[ "1", "10", "126", "1716", "24310", "352716", "5200300", "77558760", "1166803110", "17672631900", "269128937220", "4116715363800", "63205303218876", "973469712824056", "15033633249770520", "232714176627630544", "3609714217008132870", "56093138908331422716", "873065282167813104916" ]
[ "nonn", "easy", "nice" ]
73
0
5
[ "A000984", "A001448", "A001700", "A002458", "A024492", "A067001", "A100033", "A187364", "A187365" ]
null
N. J. A. Sloane
2023-03-20T08:17:22
oeisdata/seq/A002/A002458.seq
f2aa5283c4124b0bf7dccda6d846990a
A002459
Nearest integer to cosh(n).
[ "1", "2", "4", "10", "27", "74", "202", "548", "1490", "4052", "11013", "29937", "81377", "221207", "601302", "1634509", "4443055", "12077476", "32829985", "89241150", "242582598", "659407867", "1792456423", "4872401723", "13244561065", "36002449669", "97864804714", "266024120301", "723128532146", "1965667148572" ]
[ "nonn", "nice", "easy" ]
20
0
5
null
[ "M1223", "N0470" ]
N. J. A. Sloane
2021-12-19T10:07:56
oeisdata/seq/A002/A002459.seq
dcda496cc992b0a1a9b7181565fc3d72
A002460
Nearest integer to exponential integral of n.
[ "2", "5", "10", "20", "40", "86", "192", "440", "1038", "2492", "6071", "14960", "37198", "93193", "234956", "595561", "1516638", "3877904", "9950907", "25615653", "66127186", "171144671", "443966370", "1154115392", "3005950907", "7842940992", "20496497120", "53645118592", "140599195758" ]
[ "nonn", "nice" ]
30
0
5
null
[ "M1378", "N0538" ]
N. J. A. Sloane
2023-11-20T08:19:29
oeisdata/seq/A002/A002460.seq
2ad84f399a53bc6524d571bc0197f7ac
A002461
Coefficients of Legendre polynomials.
[ "1", "3", "20", "35", "126", "231", "3432", "6435", "24310", "46189", "352716", "676039", "2600150", "5014575", "155117520", "300540195", "1166803110", "2268783825", "17672631900", "34461632205", "134564468610", "263012370465", "4116715363800", "8061900920775", "31602651609438", "61989816618513", "486734856412028" ]
[ "nonn" ]
17
0
5
null
[ "M3072", "N1246" ]
N. J. A. Sloane
2015-02-02T03:48:42
oeisdata/seq/A002/A002461.seq
e923c5666724f228ce6b6fcc8813ef48
A002462
Coefficients of Legendre polynomials.
[ "1", "1", "9", "50", "1225", "7938", "106722", "736164", "41409225", "295488050", "4266847442", "31102144164", "914057459042", "6760780022500", "100583849722500", "751920156592200", "90324408810638025", "680714748752836050", "10294760089163261250", "78080479568224402500", "2375208188465386324050" ]
[ "nonn" ]
46
0
5
null
[ "M4633", "N1979" ]
N. J. A. Sloane
2025-03-31T11:55:38
oeisdata/seq/A002/A002462.seq
e4c6f7d1e344eee77298f79c18ced3e8
A002463
Coefficients of Legendre polynomials.
[ "1", "3", "30", "175", "4410", "29106", "396396", "2760615", "156434850", "1122854590", "16291599324", "119224885962", "3515605611700", "26077294372500", "388924218927000", "2913690606794775", "350671234206006450", "2647224022927695750", "40095381399899017500", "304513870316075169750" ]
[ "nonn" ]
37
0
5
null
[ "M3124", "N1267" ]
N. J. A. Sloane
2020-05-04T14:08:02
oeisdata/seq/A002/A002463.seq
157f436add97a236f07b98e70f553a62
A002464
Hertzsprung's problem: ways to arrange n non-attacking kings on an n X n board, with 1 in each row and column. Also number of permutations of length n without rising or falling successions.
[ "1", "1", "0", "0", "2", "14", "90", "646", "5242", "47622", "479306", "5296790", "63779034", "831283558", "11661506218", "175203184374", "2806878055610", "47767457130566", "860568917787402", "16362838542699862", "327460573946510746", "6880329406055690790", "151436547414562736234", "3484423186862152966838" ]
[ "nonn", "nice", "easy", "changed" ]
236
0
5
[ "A000130", "A000349", "A001100", "A001266", "A001267", "A001268", "A002464", "A002493", "A010028", "A086852", "A086853", "A086854", "A086855", "A089222", "A333706" ]
[ "M2070", "N0818" ]
N. J. A. Sloane
2025-04-12T10:28:35
oeisdata/seq/A002/A002464.seq
1fcba8b3658e2e7e7e056a9775e62884
A002465
Number of ways to place n nonattacking bishops on an n X n board.
[ "1", "1", "4", "26", "260", "3368", "53744", "1022320", "22522960", "565532992", "15915225216", "496911749920", "17029582652416", "636101065346560", "25705530908501760", "1118038500044633088", "52054862490790200576", "2584158975023147147264" ]
[ "nonn", "nice" ]
93
0
5
[ "A002465", "A187235", "A238258", "A238260", "A378590" ]
[ "M3616", "N1467" ]
N. J. A. Sloane
2025-02-16T08:32:25
oeisdata/seq/A002/A002465.seq
6c9df1f11b843b4e31be91aab1c880e4
A002466
A jumping problem.
[ "1", "1", "2", "4", "7", "13", "17", "30", "60", "107", "197", "257", "454", "908", "1619", "2981", "3889", "6870", "13740", "24499", "45109", "58849", "103958", "207916", "370723", "682597", "890513", "1573110", "3146220", "5609843", "10329173", "13475393", "23804566", "47609132", "84889091", "156302789" ]
[ "nonn", "easy" ]
28
0
5
null
[ "M1066", "N0402" ]
N. J. A. Sloane
2023-10-16T23:27:28
oeisdata/seq/A002/A002466.seq
4d046ddb6500d6316cc49e5e2d2f80a5
A002467
The game of Mousetrap with n cards (given n letters and n envelopes, how many ways are there to fill the envelopes so that at least one letter goes into its right envelope?).
[ "0", "1", "1", "4", "15", "76", "455", "3186", "25487", "229384", "2293839", "25232230", "302786759", "3936227868", "55107190151", "826607852266", "13225725636255", "224837335816336", "4047072044694047", "76894368849186894", "1537887376983737879", "32295634916658495460", "710503968166486900119" ]
[ "nonn", "easy", "nice" ]
151
0
5
[ "A002467", "A002468", "A002469", "A028306", "A047920", "A052169", "A068106", "A127899", "A276975", "A293211", "A299789", "A306234", "A324362" ]
[ "M3507", "N1423" ]
N. J. A. Sloane, Jeffrey Shallit
2025-02-16T08:32:25
oeisdata/seq/A002/A002467.seq
514032f64151429a6e4bf1839f3c2127
A002468
The game of Mousetrap with n cards: the number of permutations of n cards having at least one hit after 2.
[ "0", "0", "1", "3", "13", "65", "397", "2819", "22831", "207605", "2094121", "23205383", "280224451", "3662810249", "51523391965", "776082247979", "12463259986087", "212573743211549", "3837628837381201", "73108996989052175", "1465703611456618891", "30847249002794047793", "679998362512214208901", "15668677914172813691699", "376683592679293811722735" ]
[ "nonn", "easy", "nice" ]
58
0
5
[ "A002467", "A002468", "A002469", "A028306" ]
[ "M2945", "N1186" ]
N. J. A. Sloane
2025-02-16T08:32:25
oeisdata/seq/A002/A002468.seq
5f074a26dcb53cee8f758cd8a8f8afe6
A002469
The game of Mousetrap with n cards: the number of permutations of n cards in which 2 is the only hit.
[ "0", "0", "1", "5", "31", "203", "1501", "12449", "114955", "1171799", "13082617", "158860349", "2085208951", "29427878435", "444413828821", "7151855533913", "122190894996451", "2209057440250799", "42133729714051825", "845553296311189109", "17810791160738752207", "392911423093684031099" ]
[ "nonn", "nice" ]
60
0
5
[ "A000166", "A000255", "A002467", "A002468", "A002469", "A028306", "A159610" ]
[ "M3962", "N1635" ]
N. J. A. Sloane
2025-02-16T08:32:25
oeisdata/seq/A002/A002469.seq
1eff792995071047f812affe29514815
A002470
Glaisher's function W(n).
[ "0", "1", "4", "-8", "-48", "10", "224", "80", "-448", "-231", "40", "-248", "1408", "1466", "-2240", "-80", "1280", "-4766", "-924", "1944", "-480", "9600", "6944", "-2704", "-8704", "-15525", "5864", "-3984", "-14080", "25498", "2240", "10816", "33792", "-29760", "-19064", "800", "11088", "1994", "-54432", "-11728", "-4480" ]
[ "sign" ]
27
0
5
[ "A002286", "A002287", "A002470", "A004018", "A100130" ]
[ "M3347", "N1347" ]
N. J. A. Sloane
2019-03-04T01:53:46
oeisdata/seq/A002/A002470.seq
105bdaf3a249b578635f1ab66aae9287
A002471
Number of partitions of n into a prime and a square.
[ "0", "1", "2", "1", "1", "2", "2", "1", "1", "0", "3", "2", "1", "2", "1", "1", "2", "2", "2", "2", "2", "1", "3", "1", "0", "1", "3", "2", "2", "2", "1", "3", "2", "0", "2", "1", "1", "4", "2", "1", "3", "2", "2", "2", "2", "1", "4", "2", "1", "1", "2", "2", "3", "3", "1", "3", "2", "0", "3", "2", "1", "4", "2", "0", "2", "3", "3", "4", "2", "1", "3", "3", "2", "1", "3", "1", "4", "2", "2", "3", "1" ]
[ "nonn", "nice" ]
35
0
5
[ "A000290", "A002471", "A010051", "A064272" ]
[ "M0073", "N0025" ]
N. J. A. Sloane
2022-01-29T01:06:25
oeisdata/seq/A002/A002471.seq
2bb595e94dd0f1b8b42d21aa79fc5156
A002472
Number of pairs x,y such that y-x=2, (x,n)=1, (y,n)=1 and 1 <= x <= n.
[ "1", "1", "1", "2", "3", "1", "5", "4", "3", "3", "9", "2", "11", "5", "3", "8", "15", "3", "17", "6", "5", "9", "21", "4", "15", "11", "9", "10", "27", "3", "29", "16", "9", "15", "15", "6", "35", "17", "11", "12", "39", "5", "41", "18", "9", "21", "45", "8", "35", "15", "15", "22", "51", "9", "27", "20", "17", "27", "57", "6", "59", "29", "15", "32", "33", "9", "65", "30", "21", "15", "69", "12", "71", "35", "15", "34", "45", "11", "77", "24", "27" ]
[ "nonn", "nice", "easy", "mult" ]
69
0
5
[ "A000010", "A000265", "A002472", "A058026", "A065474", "A160467", "A319516", "A319534", "A321029", "A321030" ]
[ "M0411", "N0157" ]
N. J. A. Sloane
2024-09-20T06:13:14
oeisdata/seq/A002/A002472.seq
0e76120ee2d99b43c724de078c126ec1
A002473
7-smooth numbers: positive numbers whose prime divisors are all <= 7.
[ "1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "12", "14", "15", "16", "18", "20", "21", "24", "25", "27", "28", "30", "32", "35", "36", "40", "42", "45", "48", "49", "50", "54", "56", "60", "63", "64", "70", "72", "75", "80", "81", "84", "90", "96", "98", "100", "105", "108", "112", "120", "125", "126", "128", "135", "140", "144", "147", "150", "160", "162", "168", "175", "180", "189", "192" ]
[ "nonn", "easy", "nice" ]
131
0
5
[ "A002182", "A002473", "A003586", "A003591", "A003594", "A003595", "A006530", "A051037", "A051038", "A059405", "A063938", "A067374", "A068191", "A080197", "A080672", "A080681", "A080682", "A080683", "A195238", "A210679", "A238985", "A262401" ]
[ "M0477", "N0177" ]
N. J. A. Sloane
2025-02-16T08:32:25
oeisdata/seq/A002/A002473.seq
964d9942e46f81f67b1a1db42ae6d1eb
A002474
Denominators of coefficients of odd powers of x of the expansion of Bessel function J_1(x).
[ "2", "16", "384", "18432", "1474560", "176947200", "29727129600", "6658877030400", "1917756584755200", "690392370511872000", "303772643025223680000", "160391955517318103040000", "100084580242806496296960000", "72861574416763129304186880000", "61203722510081028615516979200000" ]
[ "nonn", "easy" ]
35
0
5
[ "A002454", "A002474", "A002506", "A010790", "A014401", "A033999", "A061403", "A061404", "A061405", "A061407", "A061440", "A061441" ]
null
N. J. A. Sloane
2025-01-05T09:40:20
oeisdata/seq/A002/A002474.seq
7054f0b86e0c42594e318e965338365f
A002475
Numbers k such that x^k + x + 1 is irreducible over GF(2).
[ "0", "2", "3", "4", "6", "7", "9", "15", "22", "28", "30", "46", "60", "63", "127", "153", "172", "303", "471", "532", "865", "900", "1366", "2380", "3310", "4495", "6321", "7447", "10198", "11425", "21846", "24369", "27286", "28713", "32767", "34353", "46383", "53484", "62481", "83406", "87382", "103468", "198958", "248833" ]
[ "nonn", "hard", "more", "nice" ]
94
0
5
[ "A001153", "A002475", "A057496", "A073639", "A223938" ]
[ "M0544", "N0194" ]
N. J. A. Sloane
2025-01-28T11:27:47
oeisdata/seq/A002/A002475.seq
5bf07f4f1d63e9cde1e7fb48e86223b0
A002476
Primes of the form 6m + 1.
[ "7", "13", "19", "31", "37", "43", "61", "67", "73", "79", "97", "103", "109", "127", "139", "151", "157", "163", "181", "193", "199", "211", "223", "229", "241", "271", "277", "283", "307", "313", "331", "337", "349", "367", "373", "379", "397", "409", "421", "433", "439", "457", "463", "487", "499", "523", "541", "547", "571", "577", "601", "607", "613", "619" ]
[ "nonn", "nice", "easy" ]
267
0
5
[ "A002476", "A003627", "A004611", "A006512", "A007528", "A016921", "A024892", "A024899", "A034936", "A045331", "A050931", "A091178", "A242660" ]
[ "M4344", "N1819" ]
N. J. A. Sloane
2025-01-05T19:51:32
oeisdata/seq/A002/A002476.seq
576f0029c653e9b588765f6f79ce80d3
A002477
Wonderful Demlo numbers: a(n) = ((10^n - 1)/9)^2.
[ "1", "121", "12321", "1234321", "123454321", "12345654321", "1234567654321", "123456787654321", "12345678987654321", "1234567900987654321", "123456790120987654321", "12345679012320987654321", "1234567901234320987654321" ]
[ "nonn", "easy" ]
118
0
5
[ "A002275", "A002477", "A080151" ]
[ "M5386", "N2339" ]
N. J. A. Sloane
2025-02-16T08:32:25
oeisdata/seq/A002/A002477.seq
999a7767e9677e07e1f7f3bca782fed4
A002478
Bisection of A000930.
[ "1", "1", "3", "6", "13", "28", "60", "129", "277", "595", "1278", "2745", "5896", "12664", "27201", "58425", "125491", "269542", "578949", "1243524", "2670964", "5736961", "12322413", "26467299", "56849086", "122106097", "262271568", "563332848", "1209982081", "2598919345", "5582216355", "11990037126", "25753389181" ]
[ "easy", "nonn", "nice" ]
131
0
5
[ "A000930", "A002478", "A008346", "A025234", "A054856", "A054857", "A077936", "A078007", "A078039", "A226546" ]
[ "M2572", "N1017" ]
N. J. A. Sloane
2024-10-17T15:15:01
oeisdata/seq/A002/A002478.seq
b0224d02312c905f63fc26d35f6449c8
A002479
Numbers of the form x^2 + 2*y^2.
[ "0", "1", "2", "3", "4", "6", "8", "9", "11", "12", "16", "17", "18", "19", "22", "24", "25", "27", "32", "33", "34", "36", "38", "41", "43", "44", "48", "49", "50", "51", "54", "57", "59", "64", "66", "67", "68", "72", "73", "75", "76", "81", "82", "83", "86", "88", "89", "96", "97", "98", "99", "100", "102", "107", "108", "113", "114", "118", "121", "123", "128", "129", "131" ]
[ "easy", "nonn", "nice" ]
78
0
5
[ "A000408", "A002479", "A003628", "A027748", "A033203", "A035251", "A097700", "A124010" ]
[ "M0547", "N0197" ]
N. J. A. Sloane
2025-01-21T11:23:55
oeisdata/seq/A002/A002479.seq
a80ea30b7c787eacbbc70db90112c14e
A002480
Numbers of the form 2x^2 + 3y^2.
[ "0", "2", "3", "5", "8", "11", "12", "14", "18", "20", "21", "27", "29", "30", "32", "35", "44", "45", "48", "50", "53", "56", "59", "62", "66", "72", "75", "77", "80", "83", "84", "93", "98", "99", "101", "107", "108", "110", "116", "120", "125", "126", "128", "131", "140", "146", "147", "149", "155", "158", "162" ]
[ "nonn" ]
25
0
5
[ "A000075", "A002480", "A002481", "A084865", "A108563" ]
[ "M0683", "N0252" ]
N. J. A. Sloane, Mira Bernstein
2024-02-18T23:35:50
oeisdata/seq/A002/A002480.seq
27cee30eb17a95c7dc122727a1ab60e1
A002481
Numbers of form x^2 + 6y^2.
[ "0", "1", "4", "6", "7", "9", "10", "15", "16", "22", "24", "25", "28", "31", "33", "36", "40", "42", "49", "54", "55", "58", "60", "63", "64", "70", "73", "79", "81", "87", "88", "90", "96", "97", "100", "103", "105", "106", "112", "118", "121", "124", "127", "132", "135", "144", "145", "150", "151", "154", "159", "160", "166", "168", "169", "175", "177", "186", "193", "196", "198", "199", "202", "214" ]
[ "nonn" ]
32
0
5
[ "A002481", "A020669", "A033199" ]
[ "M3269", "N1320" ]
N. J. A. Sloane
2020-02-05T10:37:10
oeisdata/seq/A002/A002481.seq
1cad59ec13bcebb78b3f0b32838309dd
A002482
Theta series of Borcherds' 27-dimensional unimodular lattice U_27.
[ "1", "0", "0", "2664", "101142", "1645056", "16045056", "110146176", "584713404", "2549741568", "9515943936", "31314087864", "92917622376", "252775586304", "638328674304", "1511740886400", "3387163161366", "7228598851584" ]
[ "nonn" ]
31
0
5
null
null
N. J. A. Sloane
2023-10-16T23:31:05
oeisdata/seq/A002/A002482.seq
c479f115a3a8439c39dd9d32d2fd5a8d
A002483
Expansion of Jacobi theta function {theta_1}'(q) in powers of q^(1/4).
[ "0", "2", "0", "0", "0", "0", "0", "0", "0", "-6", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "10", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "-14", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "0", "18", "0", "0", "0" ]
[ "sign" ]
28
0
5
[ "A002483", "A053187", "A245552" ]
null
N. J. A. Sloane
2017-07-24T08:24:15
oeisdata/seq/A002/A002483.seq
2a08a6711c5b8d3bb009b47b6636cba8
A002484
Number of ménage permutations.
[ "1", "2", "5", "20", "87", "616", "4843", "44128", "444621", "4936274", "59661265", "780547332", "10987097799", "165587196328", "2660378564791", "45392026278108", "819716784789209", "15620011000052754", "313219935456572497", "6593238656843759572" ]
[ "nonn", "nice", "easy" ]
33
0
5
[ "A000179", "A002484" ]
[ "M1524", "N0597" ]
N. J. A. Sloane
2015-08-03T12:25:01
oeisdata/seq/A002/A002484.seq
c1c00c6d4e11fadb0a6ab6d8bf20dafd
A002485
Numerators of convergents to Pi.
[ "0", "1", "3", "22", "333", "355", "103993", "104348", "208341", "312689", "833719", "1146408", "4272943", "5419351", "80143857", "165707065", "245850922", "411557987", "1068966896", "2549491779", "6167950454", "14885392687", "21053343141", "1783366216531", "3587785776203", "5371151992734", "8958937768937" ]
[ "nonn", "easy", "nice", "frac" ]
104
0
5
[ "A002485", "A002486", "A046947", "A072398", "A072399", "A096456" ]
[ "M3097", "N1255" ]
N. J. A. Sloane
2025-02-16T08:32:25
oeisdata/seq/A002/A002485.seq
d71107e1575ac9abc6b9b3a2e0954920
A002486
Apart from two leading terms (which are present by convention), denominators of convergents to Pi (A002485 and A046947 give numerators).
[ "1", "0", "1", "7", "106", "113", "33102", "33215", "66317", "99532", "265381", "364913", "1360120", "1725033", "25510582", "52746197", "78256779", "131002976", "340262731", "811528438", "1963319607", "4738167652", "6701487259", "567663097408", "1142027682075", "1709690779483", "2851718461558", "44485467702853" ]
[ "nonn", "easy", "nice", "frac" ]
81
0
5
[ "A002485", "A002486", "A063673", "A063674", "A072398", "A072399", "A132049", "A132050" ]
[ "M4456", "N1886" ]
N. J. A. Sloane
2025-02-16T08:32:25
oeisdata/seq/A002/A002486.seq
fdbc344b6cc0a147c9af7ab041e12f58
A002487
Stern's diatomic series (or Stern-Brocot sequence): a(0) = 0, a(1) = 1; for n > 0: a(2*n) = a(n), a(2*n+1) = a(n) + a(n+1).
[ "0", "1", "1", "2", "1", "3", "2", "3", "1", "4", "3", "5", "2", "5", "3", "4", "1", "5", "4", "7", "3", "8", "5", "7", "2", "7", "5", "8", "3", "7", "4", "5", "1", "6", "5", "9", "4", "11", "7", "10", "3", "11", "8", "13", "5", "12", "7", "9", "2", "9", "7", "12", "5", "13", "8", "11", "3", "10", "7", "11", "4", "9", "5", "6", "1", "7", "6", "11", "5", "14", "9", "13", "4", "15", "11", "18", "7", "17", "10", "13", "3", "14", "11", "19", "8", "21", "13", "18", "5", "17", "12", "19" ]
[ "nonn", "easy", "nice", "core", "look" ]
627
0
5
[ "A000032", "A000045", "A000119", "A000123", "A000360", "A001045", "A002083", "A002487", "A011655", "A020946", "A020950", "A026741", "A037227", "A046815", "A049455", "A049456", "A062092", "A064881", "A064886", "A070871", "A070872", "A071883", "A072170", "A073459", "A084091", "A086592", "A101624", "A126606", "A174980", "A174981", "A178239", "A178568", "A212288", "A212289", "A213369", "A260443", "A262097", "A277020", "A277189", "A277315", "A277325", "A277328", "A287729", "A287730", "A293160" ]
[ "M0141", "N0056" ]
N. J. A. Sloane
2025-02-16T08:32:25
oeisdata/seq/A002/A002487.seq
908188eac52ee4fce28942aa748f888a
A002488
a(n) = n^(n^n).
[ "-1", "0", "1", "16", "7625597484987" ]
[ "sign", "nice" ]
103
0
5
[ "A002488", "A002489", "A054382", "A215578" ]
[ "M5031", "N2171" ]
N. J. A. Sloane
2025-02-16T08:32:26
oeisdata/seq/A002/A002488.seq
c0b562d386ffd0f03ccd4e2c854bb79f
A002489
a(n) = n^(n^2), or (n^n)^n.
[ "1", "1", "16", "19683", "4294967296", "298023223876953125", "10314424798490535546171949056", "256923577521058878088611477224235621321607", "6277101735386680763835789423207666416102355444464034512896", "196627050475552913618075908526912116283103450944214766927315415537966391196809" ]
[ "nonn", "easy", "nice" ]
84
0
5
[ "A000312", "A001329", "A002488", "A002489", "A023813", "A023814", "A023815", "A076113", "A079172", "A079176", "A079179", "A079182", "A079186", "A079189", "A079192", "A079195", "A079198", "A090588", "A258102" ]
[ "M5030", "N2170" ]
N. J. A. Sloane
2023-10-28T11:42:59
oeisdata/seq/A002/A002489.seq
834006983e54aab940c41f5046b68277
A002490
Theta series of 27-dimensional unimodular lattice with root system A_1 and a parity vector of norm 3.
[ "1", "0", "2", "1652", "119550", "1497328", "16733124", "108084480", "588808172", "2544811584", "9516509988", "31328336284", "92876219432", "252846150384", "638250041288", "1511780647680", "3387237676950", "7228330859840", "14769380958438", "29023337216604", "55108233751768", "101433859301088" ]
[ "nonn" ]
15
0
5
[ "A000122", "A002408", "A002434", "A002490" ]
null
N. J. A. Sloane
2020-02-29T20:29:40
oeisdata/seq/A002/A002490.seq
848c845068ffe69ae5fcd17a31e4263b
A002491
Smallest number of stones in Tchoukaillon (or Mancala, or Kalahari) solitaire that make use of n-th hole.
[ "1", "2", "4", "6", "10", "12", "18", "22", "30", "34", "42", "48", "58", "60", "78", "82", "102", "108", "118", "132", "150", "154", "174", "192", "210", "214", "240", "258", "274", "282", "322", "330", "360", "372", "402", "418", "442", "454", "498", "510", "540", "570", "612", "622", "648", "672", "718", "732", "780", "802", "840", "870", "918" ]
[ "nonn", "easy", "nice" ]
105
0
5
[ "A000012", "A000960", "A002491", "A028920", "A028931", "A028932", "A028933", "A104738", "A112557", "A112558", "A113742", "A113743", "A113744", "A113745", "A113746", "A113747", "A113748", "A113749", "A344009" ]
[ "M1009", "N0377" ]
N. J. A. Sloane
2025-02-16T08:32:26
oeisdata/seq/A002/A002491.seq
e6b53b50639fc4b4e2355f3d24cafe9a
A002492
Sum of the first n even squares: 2*n*(n+1)*(2*n+1)/3.
[ "0", "4", "20", "56", "120", "220", "364", "560", "816", "1140", "1540", "2024", "2600", "3276", "4060", "4960", "5984", "7140", "8436", "9880", "11480", "13244", "15180", "17296", "19600", "22100", "24804", "27720", "30856", "34220", "37820", "41664", "45760", "50116", "54740", "59640", "64824", "70300", "76076", "82160" ]
[ "nonn", "easy", "nice" ]
176
0
5
[ "A000292", "A000330", "A002412", "A002492", "A005408", "A006331", "A016061", "A033586", "A035005", "A035006", "A035008", "A049450", "A053120", "A081277" ]
[ "M3562", "N1444" ]
N. J. A. Sloane
2023-09-01T04:41:18
oeisdata/seq/A002/A002492.seq
ad63f7936a11ffc791b805bc1d6f8fac
A002493
Number of ways to arrange n non-attacking kings on an n X n board, with 2 sides identified to form a cylinder, with 1 in each row and column.
[ "1", "0", "0", "0", "10", "60", "462", "3920", "36954", "382740", "4327510", "53088888", "702756210", "9988248956", "151751644590", "2454798429600", "42130249479562", "764681923900260", "14636063499474054", "294639009867223880" ]
[ "nonn" ]
73
0
5
[ "A002464", "A002493", "A002816", "A006184", "A338838" ]
[ "M4719", "N2017" ]
N. J. A. Sloane
2021-12-19T10:01:42
oeisdata/seq/A002/A002493.seq
85b99cb91b09e9538d00fdead6b3436a
A002494
Number of n-node graphs without isolated nodes.
[ "1", "0", "1", "2", "7", "23", "122", "888", "11302", "262322", "11730500", "1006992696", "164072174728", "50336940195360", "29003653625867536", "31397431814147073280", "63969589218557753586160", "245871863137828405125824848", "1787331789281458167615194471072", "24636021675399858912682459613241920" ]
[ "nonn", "nice" ]
63
0
5
[ "A000088", "A000612", "A001187", "A001349", "A002494", "A006129", "A006647", "A006648", "A006649", "A006650", "A006651", "A055621", "A304998" ]
[ "M1762", "N0699" ]
N. J. A. Sloane
2025-02-16T08:32:26
oeisdata/seq/A002/A002494.seq
b00a3bcb49d12818df286f0208136da0
A002495
Theta series of 27-dimensional unimodular lattice with root system A_1 with no parity vector of norm 3.
[ "1", "0", "2", "2676", "101118", "1644784", "16044996", "110148864", "584716268", "2549726784", "9515920164", "31314134428", "92917720104", "252775518960", "638328487880", "1511740834560", "3387163064214", "7228599229760", "14768913424614", "29023937463900", "55107648867544", "101434033397472" ]
[ "nonn" ]
17
0
5
[ "A000122", "A002408", "A002434", "A002490", "A002495" ]
null
N. J. A. Sloane
2020-02-29T15:16:16
oeisdata/seq/A002/A002495.seq
dc656406c5e25ed916bf9f46520ddb2d
A002496
Primes of the form k^2 + 1.
[ "2", "5", "17", "37", "101", "197", "257", "401", "577", "677", "1297", "1601", "2917", "3137", "4357", "5477", "7057", "8101", "8837", "12101", "13457", "14401", "15377", "15877", "16901", "17957", "21317", "22501", "24337", "25601", "28901", "30977", "32401", "33857", "41617", "42437", "44101", "50177" ]
[ "nonn", "easy", "nice", "changed" ]
251
0
5
[ "A000290", "A000668", "A001912", "A002496", "A002522", "A005574", "A010051", "A019434", "A028916", "A030430", "A030432", "A039770", "A054754", "A054755", "A054964", "A062325", "A063752", "A083844", "A088179", "A090693", "A141293", "A172168", "A199401", "A237040", "A243451", "A256775", "A256776", "A256777", "A256834", "A256835", "A256836", "A256837", "A256838", "A256839", "A256840", "A256841" ]
[ "M1506", "N0592" ]
N. J. A. Sloane
2025-04-23T00:15:50
oeisdata/seq/A002/A002496.seq
28b6957ba86b447b2e77115881415af4
A002497
Numbers N in A002809 such that there is rho > 0 such that for all A > 0, A008475(A)-A008475(N) >= rho*log(A/N).
[ "3", "12", "60", "420", "4620", "60060", "180180", "360360", "6126120", "116396280", "2677114440", "77636318760", "2406725881560", "89048857617720", "3651003162326520", "156993135980040360", "313986271960080720", "14757354782123793840", "14757354782123793840", "782139803452561073520", "46146248403701103337680" ]
[ "nonn", "easy", "nice" ]
34
0
5
[ "A000793", "A002201", "A002497", "A002498", "A002809", "A008475" ]
[ "M2934", "N1180" ]
N. J. A. Sloane
2023-08-23T08:35:16
oeisdata/seq/A002/A002497.seq
86b7c691f8b9548c327cb470ef8f03d0
A002498
Related to a highly composite sequence (A002497).
[ "3", "7", "12", "19", "30", "43", "49", "53", "70", "89", "112", "141", "172", "209", "250", "293", "301", "348", "368", "421", "480" ]
[ "nonn", "more" ]
26
0
5
null
[ "M2632", "N1043" ]
N. J. A. Sloane
2023-10-16T23:32:08
oeisdata/seq/A002/A002498.seq
7e0ba9c5a99c4f77a5565d0dca90204e
A002499
Number of self-converse digraphs with n nodes.
[ "1", "3", "10", "70", "708", "15224", "544152", "39576432", "5074417616", "1296033011648", "604178966756320", "556052774253161600", "954895322019762585664", "3224152068625567826724224", "20610090531322819956330186112" ]
[ "nonn", "nice" ]
38
0
5
[ "A002499", "A002500" ]
[ "M2875", "N1156" ]
N. J. A. Sloane
2020-12-31T11:02:30
oeisdata/seq/A002/A002499.seq
dd1f2ef231f5042201df7a20a3f32401
A002500
Number of self-converse relations on n points.
[ "1", "2", "8", "44", "436", "7176", "222368", "12376880", "1302871456", "254079924896", "94287450368768", "65986000800656832", "88430997899765949952", "226039101814259861321856", "1112311767839787173832758784" ]
[ "nonn", "nice", "easy" ]
23
0
5
null
[ "M1868", "N0740" ]
N. J. A. Sloane
2022-01-29T01:05:38
oeisdata/seq/A002/A002500.seq
8a47dd977d050587e73d12bcadedff6f