sequence_id
stringlengths 7
7
| sequence_name
stringlengths 4
573
| sequence
sequencelengths 1
348
| keywords
sequencelengths 1
8
| score
int64 1
2.31k
| offset_a
int64 -14,827
666,262,453B
| offset_b
int64 0
635M
⌀ | cross_references
sequencelengths 1
128
⌀ | former_ids
sequencelengths 1
3
⌀ | author
stringlengths 7
231
⌀ | timestamp
timestamp[us]date 1999-12-11 03:00:00
2025-04-28 00:58:08
| filename
stringlengths 29
29
| hash
stringlengths 32
32
|
|---|---|---|---|---|---|---|---|---|---|---|---|---|
A007701 | a(0) = 0; for n > 0, a(n) = n^n*2^((n-1)^2). | [
"0",
"1",
"8",
"432",
"131072",
"204800000",
"1565515579392",
"56593444029595648",
"9444732965739290427392",
"7146646609494406531041460224",
"24178516392292583494123520000000000"
] | [
"nonn"
] | 26 | 0 | 3 | [
"A007701",
"A086804",
"A127670"
] | [
"M4585"
] | N. J. A. Sloane | 2023-09-04T12:53:29 | oeisdata/seq/A007/A007701.seq | 35d0218647cd8cde4513b3d224d98776 |
A007702 | a(n) = prime(n)*...*prime(m), the least product of consecutive primes which is non-deficient. | [
"6",
"15015",
"33426748355",
"1357656019974967471687377449",
"7105630242567996762185122555313528897845637444413640621"
] | [
"nonn"
] | 17 | 1 | 1 | [
"A005100",
"A007684",
"A007686",
"A007702",
"A007741",
"A107705",
"A108227",
"A285993"
] | null | Walter Nissen | 2019-06-29T21:03:53 | oeisdata/seq/A007/A007702.seq | d8c4e6a3403819adade48c670da7b6ee |
A007703 | Regular primes. | [
"3",
"5",
"7",
"11",
"13",
"17",
"19",
"23",
"29",
"31",
"41",
"43",
"47",
"53",
"61",
"71",
"73",
"79",
"83",
"89",
"97",
"107",
"109",
"113",
"127",
"137",
"139",
"151",
"163",
"167",
"173",
"179",
"181",
"191",
"193",
"197",
"199",
"211",
"223",
"227",
"229",
"239",
"241",
"251",
"269",
"277",
"281",
"313",
"317",
"331",
"337",
"349",
"359",
"367",
"373",
"383",
"397",
"419",
"431"
] | [
"nonn",
"nice",
"changed"
] | 51 | 1 | 1 | [
"A000928",
"A007703",
"A061576"
] | [
"M2411"
] | N. J. A. Sloane, Simon Plouffe | 2025-04-22T10:47:58 | oeisdata/seq/A007/A007703.seq | f271d3dde5cb85520caf9c268d955051 |
A007704 | a(n+2) = (a(n) - 1)*a(n+1) + 1. | [
"2",
"3",
"4",
"9",
"28",
"225",
"6076",
"1361025",
"8268226876",
"11253255215681025",
"93044467205527772332546876",
"1047053135870867396062743192203958743681025"
] | [
"nonn",
"easy"
] | 36 | 1 | 1 | [
"A006277",
"A007704"
] | [
"M0594"
] | N. J. A. Sloane, Jeffrey Shallit | 2024-03-19T03:20:05 | oeisdata/seq/A007/A007704.seq | e7d0c80a65fd77aa1bef04a23a63023a |
A007705 | Number of ways of arranging 2n+1 nonattacking queens on a 2n+1 X 2n+1 toroidal board. | [
"1",
"0",
"10",
"28",
"0",
"88",
"4524",
"0",
"140692",
"820496",
"0",
"128850048",
"1957725000",
"0",
"605917055356",
"13404947681712",
"0"
] | [
"nonn",
"nice",
"hard",
"more"
] | 60 | 0 | 3 | [
"A007705",
"A051906",
"A071607",
"A342990"
] | [
"M4691"
] | N. J. A. Sloane | 2025-02-16T08:32:31 | oeisdata/seq/A007/A007705.seq | 1d3dcb1d90a0fb595b0f497e4a89f5be |
A007706 | a(n) = 1 + coefficient of x^n in Product_{k>=1} (1-x^k) (essentially the expansion of the Dedekind function eta(x)). | [
"2",
"0",
"0",
"1",
"1",
"2",
"1",
"2",
"1",
"1",
"1",
"1",
"0",
"1",
"1",
"0",
"1",
"1",
"1",
"1",
"1",
"1",
"2",
"1",
"1",
"1",
"2",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"0",
"1",
"1",
"1",
"1",
"0",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"2",
"1",
"1",
"1",
"1",
"1",
"2",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"0",
"1",
"1",
"1",
"1",
"1",
"1",
"0",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"2",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"2",
"1",
"1",
"1",
"1"
] | [
"nonn",
"easy",
"nice"
] | 35 | 0 | 1 | [
"A007706",
"A010815"
] | [
"M0013"
] | N. J. A. Sloane, Sep 19 1994 | 2016-08-28T18:23:35 | oeisdata/seq/A007/A007706.seq | 234ca9a35cec4bc15c351359fab33e6d |
A007707 | Prime(n)*...*prime(a(n)) is the least product of consecutive primes which is abundant. | [
"3",
"6",
"11",
"21",
"35",
"51",
"73",
"98",
"130",
"167",
"204",
"249",
"296",
"347",
"406",
"471",
"538",
"608",
"686",
"768",
"855",
"950",
"1050",
"1156",
"1266",
"1377",
"1495",
"1621",
"1755",
"1898",
"2049",
"2194",
"2347",
"2504",
"2670",
"2837",
"3013",
"3194",
"3380",
"3573",
"3771",
"3974",
"4187",
"4401",
"4625",
"4856"
] | [
"nonn"
] | 21 | 1 | 1 | [
"A005101",
"A007684",
"A007707",
"A007708",
"A007741"
] | null | Walter Nissen | 2019-06-29T21:04:25 | oeisdata/seq/A007/A007707.seq | bd6c0de45d67122f5373e5054d5b3cd3 |
A007708 | Prime(n)*...*a(n) is the least product of consecutive primes which is abundant. | [
"5",
"13",
"31",
"73",
"149",
"233",
"367",
"521",
"733",
"991",
"1249",
"1579",
"1949",
"2341",
"2791",
"3343",
"3881",
"4481",
"5147",
"5849",
"6619",
"7499",
"8387",
"9341",
"10321",
"11411",
"12517",
"13709",
"15013",
"16363",
"17881",
"19381",
"20873",
"22369",
"24007",
"25763",
"27611",
"29399",
"31357"
] | [
"nonn"
] | 18 | 1 | 1 | [
"A005101",
"A007686",
"A007707",
"A007708",
"A007741"
] | null | Walter Nissen | 2019-06-29T19:49:38 | oeisdata/seq/A007/A007708.seq | 25deddc477a0ccd85d257f2c93dc1775 |
A007709 | Number of winning (or reformed) decks at Mousetrap. | [
"1",
"1",
"2",
"6",
"15",
"84",
"330",
"1812",
"9978",
"65503",
"449719",
"3674670",
"28886593",
"266242729",
"2527701273",
"25749021720"
] | [
"nonn"
] | 23 | 1 | 3 | [
"A007709",
"A007710",
"A007711",
"A007712",
"A055459",
"A067950"
] | [
"M1608"
] | N. J. A. Sloane | 2019-06-06T04:21:08 | oeisdata/seq/A007/A007709.seq | 7a173d3b3685a973852437a2955a9807 |
A007710 | From the game of Mousetrap. | [
"1",
"0",
"2",
"6",
"31",
"180",
"1255",
"9949",
"89162",
"886837",
"9722814",
"116236256",
"1507191024",
"21042127239"
] | [
"nonn"
] | 41 | 1 | 3 | [
"A007710",
"A028305"
] | [
"M1695"
] | N. J. A. Sloane | 2018-01-17T16:44:54 | oeisdata/seq/A007/A007710.seq | dbb939bcd02c9852887fda644caed819 |
A007711 | Number of unreformed permutations of {1,...,n}. | [
"0",
"1",
"4",
"18",
"105",
"636",
"4710",
"38508",
"352902",
"3563297",
"39467081",
"475326930",
"6198134207",
"86912048471",
"1305146666727",
"20897040866280"
] | [
"nonn",
"more"
] | 31 | 1 | 3 | [
"A007709",
"A007711",
"A007712",
"A055459",
"A067950"
] | [
"M3546"
] | N. J. A. Sloane | 2018-01-17T19:08:47 | oeisdata/seq/A007/A007711.seq | 728deee40a0700923b00993735ddea75 |
A007712 | Number of once reformable permutations of {1,2,...,n}. | [
"1",
"2",
"4",
"14",
"72",
"316",
"1730",
"9728",
"64330",
"444890",
"3645441",
"28758111",
"265434293",
"2522822881",
"25717118338"
] | [
"nonn",
"nice",
"more"
] | 20 | 2 | 2 | [
"A007709",
"A007711",
"A007712",
"A055459",
"A067950"
] | [
"M1283"
] | N. J. A. Sloane | 2019-06-06T05:51:32 | oeisdata/seq/A007/A007712.seq | 12ab298a0bf9ecdecfbdde085874e779 |
A007713 | Number of 4-level rooted trees with n leaves. | [
"1",
"1",
"4",
"10",
"30",
"75",
"206",
"518",
"1344",
"3357",
"8429",
"20759",
"51044",
"123973",
"299848",
"719197",
"1716563",
"4070800",
"9607797",
"22555988",
"52718749",
"122655485",
"284207304",
"655894527",
"1508046031",
"3454808143",
"7887768997",
"17949709753",
"40719611684",
"92096461012",
"207697731344"
] | [
"easy",
"nonn"
] | 40 | 0 | 3 | [
"A001970",
"A007713",
"A047968",
"A050342",
"A055886",
"A089259",
"A141268",
"A258466",
"A261049",
"A290353",
"A319066",
"A320328",
"A320330",
"A320331"
] | null | N. J. A. Sloane. | 2023-02-18T14:45:11 | oeisdata/seq/A007/A007713.seq | 18e50ac8b05bed69e1e498c88e49a1ae |
A007714 | Number of 5-level rooted trees with n leaves. | [
"1",
"1",
"5",
"15",
"55",
"170",
"571",
"1789",
"5727",
"17836",
"55627",
"171169",
"524879",
"1595896",
"4829894",
"14527981",
"43497312",
"129588391",
"384430264",
"1135607519",
"3341662498",
"9796626673",
"28620419254",
"83334382425",
"241879403752",
"699937499318",
"2019607806247",
"5811320364410",
"16677611788799"
] | [
"easy",
"nonn"
] | 38 | 0 | 3 | [
"A007714",
"A290353"
] | null | N. J. A. Sloane | 2019-04-08T03:41:21 | oeisdata/seq/A007/A007714.seq | e4da506588ebf3907a1ba65409c4a894 |
A007715 | Number of 5-leaf rooted trees with n levels. | [
"1",
"7",
"27",
"75",
"170",
"336",
"602",
"1002",
"1575",
"2365",
"3421",
"4797",
"6552",
"8750",
"11460",
"14756",
"18717",
"23427",
"28975",
"35455",
"42966",
"51612",
"61502",
"72750",
"85475",
"99801",
"115857",
"133777",
"153700",
"175770",
"200136",
"226952",
"256377",
"288575",
"323715",
"361971",
"403522",
"448552",
"497250"
] | [
"nonn",
"easy"
] | 36 | 1 | 2 | [
"A007715",
"A290353"
] | null | N. J. A. Sloane, Simon Plouffe | 2022-09-08T08:44:35 | oeisdata/seq/A007/A007715.seq | 8358dd7eee279c70fedbe5a6009108cb |
A007716 | Number of polynomial symmetric functions of matrix of order n under separate row and column permutations. | [
"1",
"1",
"4",
"10",
"33",
"91",
"298",
"910",
"3017",
"9945",
"34207",
"119369",
"429250",
"1574224",
"5916148",
"22699830",
"89003059",
"356058540",
"1453080087",
"6044132794",
"25612598436",
"110503627621",
"485161348047",
"2166488899642",
"9835209912767",
"45370059225318",
"212582817739535",
"1011306624512711"
] | [
"nice",
"nonn"
] | 55 | 0 | 3 | [
"A000041",
"A007716",
"A049311",
"A052365",
"A052366",
"A052367",
"A052372",
"A052373",
"A053307",
"A054688",
"A318795"
] | null | Colin Mallows | 2020-03-29T19:35:31 | oeisdata/seq/A007/A007716.seq | 55047f7e190fa13c6d0c802320031d2b |
A007717 | Number of symmetric polynomial functions of degree n of a symmetric matrix (of indefinitely large size) under joint row and column permutations. Also number of multigraphs with n edges (allowing loops) on an infinite set of nodes. | [
"1",
"2",
"7",
"23",
"79",
"274",
"1003",
"3763",
"14723",
"59663",
"250738",
"1090608",
"4905430",
"22777420",
"109040012",
"537401702",
"2723210617",
"14170838544",
"75639280146",
"413692111521",
"2316122210804",
"13261980807830",
"77598959094772",
"463626704130058",
"2826406013488180",
"17569700716557737"
] | [
"nonn"
] | 67 | 0 | 2 | [
"A000664",
"A002620",
"A007716",
"A007717",
"A007719",
"A020555",
"A050531",
"A050532",
"A050535",
"A052171",
"A053418",
"A053419",
"A094574",
"A316972",
"A316974",
"A318951",
"A331485",
"A339065"
] | null | Colin Mallows | 2025-02-08T11:08:59 | oeisdata/seq/A007/A007717.seq | c9bc664a1989469cb11a96e40baa196a |
A007718 | Number of independent polynomial invariants of matrix of order n. | [
"1",
"1",
"3",
"6",
"17",
"40",
"125",
"354",
"1159",
"3774",
"13113",
"46426",
"171027",
"644038",
"2493848",
"9867688",
"39922991",
"164747459",
"693093407",
"2968918400",
"12940917244",
"57353242370",
"258306634422",
"1181572250326",
"5486982683756",
"25856584485254"
] | [
"nonn"
] | 18 | 0 | 3 | [
"A007716",
"A007718",
"A056156",
"A319557",
"A319565",
"A319566"
] | null | Colin Mallows | 2023-01-15T19:49:25 | oeisdata/seq/A007/A007718.seq | 2763994036e304a28949417579c1b58b |
A007719 | Number of independent polynomial invariants of symmetric matrix of order n. | [
"1",
"2",
"4",
"11",
"30",
"95",
"328",
"1211",
"4779",
"19902",
"86682",
"393072",
"1847264",
"8965027",
"44814034",
"230232789",
"1213534723",
"6552995689",
"36207886517",
"204499421849",
"1179555353219",
"6942908667578",
"41673453738272",
"254918441681030",
"1588256152307002",
"10073760672179505"
] | [
"nonn",
"nice"
] | 39 | 0 | 2 | [
"A002905",
"A007716",
"A007717",
"A007719",
"A020555",
"A050535",
"A053419",
"A076864",
"A191970",
"A316972",
"A316974",
"A322115"
] | null | Colin Mallows | 2019-10-23T14:35:38 | oeisdata/seq/A007/A007719.seq | 375e05ebdd4b6d5392b70633fb45f63f |
A007720 | Arises in attempts to apply Engel's `probabilistic abacus' to random walks on infinite square grid. | [
"1",
"2",
"3",
"1",
"2",
"3",
"4",
"2",
"3",
"3",
"2",
"3",
"4",
"4",
"4",
"3",
"4",
"5",
"5",
"3",
"4",
"5",
"3",
"4",
"5",
"5",
"6",
"4",
"5",
"6",
"4",
"5",
"5",
"6",
"7",
"5",
"5",
"6",
"4",
"5",
"4",
"5",
"5",
"5",
"4",
"4",
"5",
"6",
"6",
"5",
"5",
"5",
"4",
"5",
"6",
"6",
"6",
"4",
"5",
"4",
"5",
"5",
"7",
"7"
] | [
"nonn",
"walk"
] | 6 | 1 | 2 | null | null | N. J. A. Sloane, James Propp | 2013-10-12T15:25:23 | oeisdata/seq/A007/A007720.seq | 44a77e478467c164f522c54c6970bbdd |
A007721 | Number of distinct degree sequences among all connected graphs with n nodes. | [
"1",
"1",
"2",
"6",
"19",
"68",
"236",
"863",
"3137",
"11636",
"43306",
"162728",
"614142",
"2330454",
"8875656",
"33924699",
"130038017",
"499753560",
"1924912505",
"7429159770",
"28723877046",
"111236422377",
"431403469046",
"1675316533812",
"6513837677642",
"25354842098354",
"98794053266471",
"385312558567775"
] | [
"nonn",
"nice"
] | 46 | 1 | 3 | [
"A000569",
"A004250",
"A004251",
"A007721",
"A007722",
"A029889",
"A095268"
] | null | Frank Ruskey | 2017-06-25T02:50:58 | oeisdata/seq/A007/A007721.seq | e1ffe468be5c8dc10846754e5f216623 |
A007722 | Number of graphical partitions of biconnected graphs with n nodes. | [
"1",
"3",
"9",
"34",
"125",
"473",
"1779",
"6732",
"25492",
"96927",
"369463",
"1412700",
"5415117",
"20807502",
"80120350",
"309106496",
"1194609429",
"4624160156",
"17925278497",
"69578272204",
"270401326899",
"1052036082719",
"4097343156323",
"15973179953261",
"62325892264031",
"243392644741599"
] | [
"nonn"
] | 27 | 3 | 2 | [
"A000569",
"A004250",
"A004251",
"A007721",
"A007722",
"A029889",
"A095268"
] | null | Frank Ruskey | 2023-11-29T11:41:51 | oeisdata/seq/A007/A007722.seq | b7330e726e0e9862cccdbc3dbf53508a |
A007723 | Triangle a(n,k) of number of M-sequences read by antidiagonals. | [
"1",
"1",
"2",
"1",
"2",
"2",
"1",
"2",
"3",
"2",
"1",
"2",
"4",
"4",
"2",
"1",
"2",
"5",
"8",
"5",
"2",
"1",
"2",
"6",
"15",
"16",
"6",
"2",
"1",
"2",
"7",
"26",
"52",
"32",
"7",
"2",
"1",
"2",
"8",
"42",
"152",
"203",
"64",
"8",
"2",
"1",
"2",
"9",
"64",
"392",
"1144",
"877",
"128",
"9",
"2",
"1",
"2",
"10",
"93",
"904",
"5345",
"10742",
"4140",
"256",
"10",
"2",
"1",
"2",
"11",
"130",
"1899",
"20926",
"102050",
"122772",
"21147"
] | [
"nonn",
"nice",
"easy",
"tabl"
] | 31 | 0 | 3 | [
"A003659",
"A007065",
"A007625",
"A007723",
"A011819",
"A011820"
] | null | N. J. A. Sloane | 2024-08-06T07:07:13 | oeisdata/seq/A007/A007723.seq | 5b0c58f688e67eeaba1f865d96717598 |
A007724 | Even minus odd extensions of truncated 3 X 2n grid diagram. | [
"2",
"12",
"110",
"1274",
"17136",
"255816",
"4124406",
"70549050",
"1264752060",
"23555382240",
"452806924752",
"8939481277552",
"180551099694400",
"3719061442253520",
"77933728043586630",
"1658001861319441050",
"35749633305661575300",
"780123576993991461000",
"17208112644166765652100"
] | [
"nonn",
"easy"
] | 33 | 2 | 1 | [
"A003121",
"A005789",
"A007724",
"A217800"
] | null | Frank Ruskey | 2023-07-07T13:15:27 | oeisdata/seq/A007/A007724.seq | 37a830d767076c66f73b8bd587bcee21 |
A007725 | Number of spanning trees of Aztec diamonds of order n. | [
"1",
"4",
"768",
"18170880",
"48466759778304",
"14179455913065873408000",
"449549878218740179750040371200000",
"1534679662450485063038349752542766158611218432",
"561985025597966566291275288056092110323394467225010519932928"
] | [
"nonn"
] | 54 | 0 | 2 | [
"A007725",
"A007726",
"A340166",
"A340176",
"A340185",
"A340352"
] | null | Richard Stanley | 2023-02-28T23:46:15 | oeisdata/seq/A007/A007725.seq | 057aa5d4c43e741dc3d41b16dc6df924 |
A007726 | Number of spanning trees of quarter Aztec diamonds of order n. | [
"1",
"1",
"4",
"56",
"2640",
"411840",
"210613312",
"351102230528",
"1901049105201408",
"33349238079515381760",
"1892086487183556298556416",
"346728396311328694807284940800",
"205021218459835103075295973360128000",
"390870571052378289975757743555515137130496"
] | [
"nonn"
] | 43 | 1 | 3 | [
"A007341",
"A007725",
"A007726",
"A065072",
"A340052"
] | null | Richard Stanley | 2025-01-11T03:33:28 | oeisdata/seq/A007/A007726.seq | f7c79ec781b9f4832a21b742a9a28bf5 |
A007727 | Number of 2n-bead black-white strings with n black beads and fundamental period 2n. | [
"1",
"2",
"4",
"18",
"64",
"250",
"900",
"3430",
"12800",
"48600",
"184500",
"705430",
"2703168",
"10400598",
"40113164",
"155117250",
"601067520",
"2333606218",
"9075085776",
"35345263798",
"137846344000",
"538257870990",
"2104098258284",
"8233430727598",
"32247600966144"
] | [
"nonn"
] | 24 | 0 | 2 | [
"A007727",
"A022553",
"A045630",
"A060165"
] | null | Doug Bowman, bowman(AT)math.uiuc.edu. | 2023-05-05T10:59:55 | oeisdata/seq/A007/A007727.seq | 5acb7231a31ab0616ceae26a378a1d43 |
A007728 | 5th binary partition function. | [
"1",
"1",
"2",
"2",
"4",
"3",
"5",
"4",
"8",
"6",
"9",
"7",
"12",
"8",
"12",
"9",
"17",
"12",
"18",
"14",
"23",
"15",
"22",
"16",
"28",
"19",
"27",
"20",
"32",
"20",
"29",
"21",
"38",
"26",
"38",
"29",
"47",
"30",
"44",
"32",
"55",
"37",
"52",
"38",
"60",
"37",
"53",
"38",
"66",
"44",
"63",
"47",
"74",
"46",
"66",
"47",
"79",
"52",
"72",
"52",
"81",
"49",
"70",
"50",
"88",
"59",
"85",
"64"
] | [
"nonn",
"look"
] | 34 | 0 | 3 | [
"A000123",
"A007728",
"A018819",
"A072170"
] | null | N. J. A. Sloane | 2023-08-02T14:36:46 | oeisdata/seq/A007/A007728.seq | f6d563c9932986cdf7bc78d1a52061e3 |
A007729 | 6th binary partition function. | [
"1",
"2",
"4",
"5",
"8",
"10",
"13",
"14",
"18",
"21",
"26",
"28",
"33",
"36",
"40",
"41",
"46",
"50",
"57",
"60",
"68",
"73",
"80",
"82",
"89",
"94",
"102",
"105",
"112",
"116",
"121",
"122",
"128",
"133",
"142",
"146",
"157",
"164",
"174",
"177",
"188",
"196",
"209",
"214",
"226",
"233",
"242",
"244",
"253",
"260",
"272",
"277",
"290",
"298",
"309",
"312",
"322",
"329",
"340",
"344"
] | [
"nonn"
] | 57 | 0 | 2 | [
"A002487",
"A007051",
"A007729",
"A072170",
"A174868"
] | null | N. J. A. Sloane | 2023-05-08T03:25:07 | oeisdata/seq/A007/A007729.seq | 9798145d6e040dddd8ad59ee8d229866 |
A007730 | 7th binary partition function. | [
"1",
"1",
"2",
"2",
"4",
"4",
"6",
"5",
"9",
"8",
"12",
"10",
"16",
"14",
"19",
"15",
"24",
"20",
"28",
"22",
"34",
"29",
"39",
"30",
"46",
"38",
"52",
"40",
"59",
"49",
"64",
"48",
"72",
"58",
"78",
"59",
"87",
"72",
"94",
"70",
"104",
"84",
"113",
"85",
"124",
"102",
"132",
"98",
"144",
"115",
"153",
"114",
"166",
"136",
"176",
"130",
"189",
"151",
"200",
"148",
"212",
"172",
"220"
] | [
"nonn"
] | 30 | 0 | 3 | [
"A007730",
"A072170"
] | null | N. J. A. Sloane | 2021-02-20T03:35:58 | oeisdata/seq/A007/A007730.seq | 8d6d15a828e5ad539bddcfcdf6bf59e4 |
A007731 | a(n) = a(floor(n/2)) + a(floor(n/3)) + a(floor(n/6)), with a(0) = 1. | [
"1",
"3",
"5",
"7",
"9",
"9",
"15",
"15",
"17",
"19",
"19",
"19",
"29",
"29",
"29",
"29",
"31",
"31",
"41",
"41",
"41",
"41",
"41",
"41",
"55",
"55",
"55",
"57",
"57",
"57",
"57",
"57",
"59",
"59",
"59",
"59",
"85",
"85",
"85",
"85",
"85",
"85",
"85",
"85",
"85",
"85",
"85",
"85",
"103",
"103",
"103",
"103",
"103",
"103",
"117",
"117"
] | [
"nonn",
"easy",
"nice"
] | 38 | 0 | 2 | [
"A007731",
"A061984",
"A083662",
"A088468",
"A165704",
"A165706"
] | null | N. J. A. Sloane | 2025-04-10T10:45:59 | oeisdata/seq/A007/A007731.seq | 3162db4ddb29884195b821c977822c15 |
A007732 | Period of decimal representation of 1/n. | [
"1",
"1",
"1",
"1",
"1",
"1",
"6",
"1",
"1",
"1",
"2",
"1",
"6",
"6",
"1",
"1",
"16",
"1",
"18",
"1",
"6",
"2",
"22",
"1",
"1",
"6",
"3",
"6",
"28",
"1",
"15",
"1",
"2",
"16",
"6",
"1",
"3",
"18",
"6",
"1",
"5",
"6",
"21",
"2",
"1",
"22",
"46",
"1",
"42",
"1",
"16",
"6",
"13",
"3",
"2",
"6",
"18",
"28",
"58",
"1",
"60",
"15",
"6",
"1",
"6",
"2",
"33",
"16",
"22",
"6",
"35",
"1",
"8",
"3",
"1",
"18",
"6",
"6",
"13",
"1",
"9",
"5",
"41",
"6",
"16",
"21",
"28",
"2",
"44",
"1"
] | [
"nonn",
"base",
"easy",
"nice"
] | 92 | 1 | 7 | [
"A001913",
"A007732",
"A066799",
"A084680",
"A121090",
"A121341"
] | null | N. J. A. Sloane, Hal Sampson [ hals(AT)easynet.com ] | 2024-07-18T03:33:00 | oeisdata/seq/A007/A007732.seq | fc4ab7b7104f389cbb7dc4e56dbff136 |
A007733 | Period of binary representation of 1/n. Also, multiplicative order of 2 modulo the odd part of n (= A000265(n)). | [
"1",
"1",
"2",
"1",
"4",
"2",
"3",
"1",
"6",
"4",
"10",
"2",
"12",
"3",
"4",
"1",
"8",
"6",
"18",
"4",
"6",
"10",
"11",
"2",
"20",
"12",
"18",
"3",
"28",
"4",
"5",
"1",
"10",
"8",
"12",
"6",
"36",
"18",
"12",
"4",
"20",
"6",
"14",
"10",
"12",
"11",
"23",
"2",
"21",
"20",
"8",
"12",
"52",
"18",
"20",
"3",
"18",
"28",
"58",
"4",
"60",
"5",
"6",
"1",
"12",
"10",
"66",
"8",
"22",
"12",
"35",
"6",
"9",
"36",
"20",
"18",
"30",
"12",
"39",
"4",
"54",
"20",
"82",
"6"
] | [
"nonn",
"easy"
] | 58 | 1 | 3 | [
"A000265",
"A002326",
"A007733",
"A136042",
"A139099",
"A256607",
"A256757"
] | null | N. J. A. Sloane, Hal Sampson (hals(AT)easynet.com) | 2022-12-21T12:00:39 | oeisdata/seq/A007/A007733.seq | fcc383bb5282b02ad2b9dccc3d492614 |
A007734 | Period of repeating digits of 1/n in base 3. | [
"1",
"1",
"1",
"2",
"4",
"1",
"6",
"2",
"1",
"4",
"5",
"2",
"3",
"6",
"4",
"4",
"16",
"1",
"18",
"4",
"6",
"5",
"11",
"2",
"20",
"3",
"1",
"6",
"28",
"4",
"30",
"8",
"5",
"16",
"12",
"2",
"18",
"18",
"3",
"4",
"8",
"6",
"42",
"10",
"4",
"11",
"23",
"4",
"42",
"20",
"16",
"6",
"52",
"1",
"20",
"6",
"18",
"28",
"29",
"4",
"10",
"30",
"6",
"16",
"12",
"5",
"22",
"16",
"11",
"12",
"35",
"2",
"12",
"18",
"20",
"18",
"30",
"3",
"78",
"4",
"1",
"8",
"41",
"6",
"16",
"42"
] | [
"nonn",
"base"
] | 21 | 1 | 4 | null | null | N. J. A. Sloane, Hal Sampson (hals(AT)easynet.com) | 2014-02-13T13:17:12 | oeisdata/seq/A007/A007734.seq | f1a6ccc31465efd76227a8a67859f260 |
A007735 | Period of base 4 representation of 1/n. | [
"1",
"1",
"1",
"1",
"2",
"1",
"3",
"1",
"3",
"2",
"5",
"1",
"6",
"3",
"2",
"1",
"4",
"3",
"9",
"2",
"3",
"5",
"11",
"1",
"10",
"6",
"9",
"3",
"14",
"2",
"5",
"1",
"5",
"4",
"6",
"3",
"18",
"9",
"6",
"2",
"10",
"3",
"7",
"5",
"6",
"11",
"23",
"1",
"21",
"10",
"4",
"6",
"26",
"9",
"10",
"3",
"9",
"14",
"29",
"2",
"30",
"5",
"3",
"1",
"6",
"5",
"33",
"4",
"11",
"6",
"35",
"3",
"9",
"18",
"10",
"9",
"15",
"6",
"39",
"2",
"27",
"10",
"41",
"3",
"4",
"7",
"14",
"5",
"11",
"6",
"6",
"11",
"5"
] | [
"nonn",
"base"
] | 22 | 1 | 5 | [
"A007732",
"A007733",
"A007734",
"A007735",
"A007736",
"A007737",
"A007738",
"A007739",
"A007740"
] | null | N. J. A. Sloane, Hal Sampson (hals(AT)easynet.com) | 2024-08-26T04:54:45 | oeisdata/seq/A007/A007735.seq | 1234267a6bbc244470b6945ae5238d2f |
A007736 | Period of repeating digits of 1/n in base 5. | [
"1",
"1",
"2",
"1",
"1",
"2",
"6",
"2",
"6",
"1",
"5",
"2",
"4",
"6",
"2",
"4",
"16",
"6",
"9",
"1",
"6",
"5",
"22",
"2",
"1",
"4",
"18",
"6",
"14",
"2",
"3",
"8",
"10",
"16",
"6",
"6",
"36",
"9",
"4",
"2",
"20",
"6",
"42",
"5",
"6",
"22",
"46",
"4",
"42",
"1",
"16",
"4",
"52",
"18",
"5",
"6",
"18",
"14",
"29",
"2",
"30",
"3",
"6",
"16",
"4",
"10",
"22",
"16",
"22",
"6",
"5",
"6",
"72",
"36",
"2",
"9",
"30",
"4",
"39",
"4",
"54",
"20",
"82",
"6",
"16",
"42",
"14",
"10",
"44"
] | [
"nonn",
"base"
] | 29 | 1 | 3 | null | null | N. J. A. Sloane, Hal Sampson (hals(AT)easynet.com), David W. Wilson | 2024-07-10T20:31:56 | oeisdata/seq/A007/A007736.seq | c0f973d98b8673a65d61b5f61d988a1b |
A007737 | Period of repeating digits of 1/n in base 6. | [
"1",
"1",
"1",
"1",
"1",
"1",
"2",
"1",
"1",
"1",
"10",
"1",
"12",
"2",
"1",
"1",
"16",
"1",
"9",
"1",
"2",
"10",
"11",
"1",
"5",
"12",
"1",
"2",
"14",
"1",
"6",
"1",
"10",
"16",
"2",
"1",
"4",
"9",
"12",
"1",
"40",
"2",
"3",
"10",
"1",
"11",
"23",
"1",
"14",
"5",
"16",
"12",
"26",
"1",
"10",
"2",
"9",
"14",
"58",
"1",
"60",
"6",
"2",
"1",
"12",
"10",
"33",
"16",
"11",
"2",
"35",
"1",
"36",
"4",
"5",
"9",
"10",
"12",
"78",
"1",
"1",
"40",
"82",
"2",
"16",
"3",
"14",
"10"
] | [
"nonn",
"base"
] | 28 | 1 | 7 | [
"A007732",
"A007733",
"A007734",
"A007735",
"A007736",
"A007737",
"A007738",
"A007739",
"A007740"
] | null | N. J. A. Sloane, Hal Sampson (hals(AT)easynet.com) | 2024-08-26T04:55:29 | oeisdata/seq/A007/A007737.seq | 9a70dad511a71b2818bfa64afc92bd5e |
A007738 | Period of repeating digits of 1/n in base 7. | [
"1",
"1",
"1",
"2",
"4",
"1",
"1",
"2",
"3",
"4",
"10",
"2",
"12",
"1",
"4",
"2",
"16",
"3",
"3",
"4",
"1",
"10",
"22",
"2",
"4",
"12",
"9",
"2",
"7",
"4",
"15",
"4",
"10",
"16",
"4",
"6",
"9",
"3",
"12",
"4",
"40",
"1",
"6",
"10",
"12",
"22",
"23",
"2",
"1",
"4",
"16",
"12",
"26",
"9",
"20",
"2",
"3",
"7",
"29",
"4",
"60",
"15",
"3",
"8",
"12",
"10",
"66",
"16",
"22",
"4",
"70",
"6",
"24",
"9",
"4",
"6",
"10",
"12",
"78",
"4",
"27",
"40",
"41",
"2",
"16",
"6",
"7",
"10"
] | [
"nonn",
"base"
] | 19 | 1 | 4 | null | null | N. J. A. Sloane, Hal Sampson (hals(AT)easynet.com) | 2014-02-14T00:33:51 | oeisdata/seq/A007/A007738.seq | 0d66084a9302ab76d1adb1ca82894961 |
A007739 | Period of repeating digits of 1/n in base 8. | [
"1",
"1",
"2",
"1",
"4",
"2",
"1",
"1",
"2",
"4",
"10",
"2",
"4",
"1",
"4",
"1",
"8",
"2",
"6",
"4",
"2",
"10",
"11",
"2",
"20",
"4",
"6",
"1",
"28",
"4",
"5",
"1",
"10",
"8",
"4",
"2",
"12",
"6",
"4",
"4",
"20",
"2",
"14",
"10",
"4",
"11",
"23",
"2",
"7",
"20",
"8",
"4",
"52",
"6",
"20",
"1",
"6",
"28",
"58",
"4",
"20",
"5",
"2",
"1",
"4",
"10",
"22",
"8",
"22",
"4",
"35",
"2",
"3",
"12",
"20",
"6",
"10",
"4",
"13",
"4",
"18",
"20",
"82",
"2",
"8",
"14",
"28",
"10",
"11",
"4",
"4"
] | [
"nonn",
"base"
] | 24 | 1 | 3 | [
"A007732",
"A007733",
"A007734",
"A007735",
"A007736",
"A007737",
"A007738",
"A007739",
"A007740"
] | null | N. J. A. Sloane, Hal Sampson (hals(AT)easynet.com) | 2024-08-26T04:55:45 | oeisdata/seq/A007/A007739.seq | abf682d80d11ded7c049867fab5754c3 |
A007740 | Period of repeating digits of 1/n in base 9. | [
"1",
"1",
"1",
"1",
"2",
"1",
"3",
"1",
"1",
"2",
"5",
"1",
"3",
"3",
"2",
"2",
"8",
"1",
"9",
"2",
"3",
"5",
"11",
"1",
"10",
"3",
"1",
"3",
"14",
"2",
"15",
"4",
"5",
"8",
"6",
"1",
"9",
"9",
"3",
"2",
"4",
"3",
"21",
"5",
"2",
"11",
"23",
"2",
"21",
"10",
"8",
"3",
"26",
"1",
"10",
"3",
"9",
"14",
"29",
"2",
"5",
"15",
"3",
"8",
"6",
"5",
"11",
"8",
"11",
"6",
"35",
"1",
"6",
"9",
"10",
"9",
"15",
"3",
"39",
"2",
"1",
"4",
"41",
"3",
"8",
"21",
"14",
"5",
"44",
"2",
"3",
"11",
"15",
"23"
] | [
"nonn",
"base"
] | 29 | 1 | 5 | [
"A007732",
"A007733",
"A007734",
"A007735",
"A007736",
"A007737",
"A007738",
"A007739",
"A007740"
] | null | N. J. A. Sloane, Hal Sampson (hals(AT)easynet.com) | 2024-08-26T04:56:02 | oeisdata/seq/A007/A007740.seq | 242826822f600926640aa205f350bf92 |
A007741 | a(n) = prime(n)*...*prime(m), the least product of consecutive primes which is abundant. | [
"30",
"15015",
"33426748355",
"1357656019974967471687377449",
"7105630242567996762185122555313528897845637444413640621"
] | [
"nonn"
] | 34 | 1 | 1 | [
"A005101",
"A006038",
"A007702",
"A007707",
"A007708",
"A007741",
"A091191",
"A108227",
"A285993"
] | null | Walter Nissen | 2019-06-29T19:52:00 | oeisdata/seq/A007/A007741.seq | 1eb381101a05029d743bd1ea9a6222e3 |
A007742 | a(n) = n*(4*n+1). | [
"0",
"5",
"18",
"39",
"68",
"105",
"150",
"203",
"264",
"333",
"410",
"495",
"588",
"689",
"798",
"915",
"1040",
"1173",
"1314",
"1463",
"1620",
"1785",
"1958",
"2139",
"2328",
"2525",
"2730",
"2943",
"3164",
"3393",
"3630",
"3875",
"4128",
"4389",
"4658",
"4935",
"5220",
"5513",
"5814",
"6123",
"6440",
"6765",
"7098",
"7439",
"7788",
"8145"
] | [
"nonn",
"easy",
"nice"
] | 104 | 0 | 2 | [
"A000217",
"A000290",
"A000384",
"A001107",
"A002061",
"A002378",
"A002620",
"A002939",
"A002943",
"A007742",
"A014105",
"A016742",
"A016754",
"A033951",
"A033952",
"A033953",
"A033954",
"A033988",
"A033989",
"A033990",
"A033991",
"A033996",
"A035608",
"A053755",
"A054552",
"A054554",
"A054556",
"A054567",
"A054569",
"A074378",
"A080335",
"A081266",
"A137932",
"A140090",
"A156859",
"A267682",
"A317186"
] | null | N. J. A. Sloane | 2024-05-31T05:52:04 | oeisdata/seq/A007/A007742.seq | e2d5408465c3a21c7eaf2dd071c11647 |
A007743 | Number of achiral polyominoes with n cubical cells of the regular tiling with Schläfli symbol {4,3,4} (or polycubes). | [
"1",
"1",
"2",
"6",
"17",
"58",
"191",
"700",
"2515",
"9623",
"36552",
"143761",
"564443",
"2259905",
"9057278",
"36705846",
"149046429",
"609246350",
"2495727647",
"10267016450",
"42322763940",
"174974139365"
] | [
"nonn",
"nice"
] | 22 | 1 | 3 | [
"A000162",
"A001931",
"A007743",
"A038119",
"A371397"
] | null | Arlin Anderson (starship1(AT)gmail.com) | 2024-09-20T06:06:29 | oeisdata/seq/A007/A007743.seq | bd6dc68e73fcec804fd903b0acce35ed |
A007744 | Expansion of (1+6*x)/(1-4*x)^(7/2). | [
"1",
"20",
"210",
"1680",
"11550",
"72072",
"420420",
"2333760",
"12471030",
"64664600",
"327202876",
"1622493600",
"7909656300",
"38003792400",
"180324117000",
"846321189120",
"3934071152550",
"18132120329400",
"82937661506700"
] | [
"nonn",
"changed"
] | 43 | 0 | 2 | null | null | N. J. A. Sloane | 2025-04-24T02:14:05 | oeisdata/seq/A007/A007744.seq | aaf4bac58b999627b264ddb0abbfd510 |
A007745 | a(n) = n OR n^2 (applied to binary expansions). | [
"1",
"6",
"11",
"20",
"29",
"38",
"55",
"72",
"89",
"110",
"123",
"156",
"173",
"206",
"239",
"272",
"305",
"342",
"379",
"404",
"445",
"502",
"535",
"600",
"633",
"702",
"731",
"796",
"861",
"926",
"991",
"1056",
"1121",
"1190",
"1259",
"1332",
"1405",
"1446",
"1527",
"1640",
"1721",
"1774",
"1851",
"1980",
"2029",
"2158",
"2223",
"2352",
"2417",
"2550"
] | [
"base",
"nonn",
"easy"
] | 36 | 1 | 2 | [
"A002378",
"A007745",
"A169810",
"A213541"
] | null | J. P. Mocquard and D. Bouchon (BOUCHON(AT)zeus.univ-poitiers.fr) | 2022-09-08T08:44:35 | oeisdata/seq/A007/A007745.seq | cb0e37aec53527053440f326bedb24c2 |
A007746 | Number of ways for n-3 nonintersecting loops to cross a line 2n times. | [
"42",
"640",
"5894",
"42840",
"271240",
"1569984",
"8536890",
"44346456",
"222516030",
"1086685600",
"5193298110",
"24384586200",
"112831907760",
"515709552000",
"2332549535400",
"10455495457248",
"46500885666900",
"205401168733824",
"901819865269180",
"3938266773556720",
"17116175702216624"
] | [
"nonn"
] | 21 | 4 | 1 | [
"A007746",
"A008828"
] | null | Philippe Di Francesco (philippe(AT)amoco.saclay.cea.fr) | 2022-09-08T08:44:35 | oeisdata/seq/A007/A007746.seq | fd7f51938877970185194a687c06364e |
A007747 | Number of nonnegative integer points (p_1,p_2,...,p_n) in polytope defined by p_0 = p_{n+1} = 0, 2p_i - (p_{i+1} + p_{i-1}) <= 2, p_i >= 0, i=1,...,n. Number of score sequences in a chess tournament with n+1 players (with 3 outcomes for each game). | [
"1",
"2",
"5",
"16",
"59",
"247",
"1111",
"5302",
"26376",
"135670",
"716542",
"3868142",
"21265884",
"118741369",
"671906876",
"3846342253",
"22243294360",
"129793088770",
"763444949789",
"4522896682789",
"26968749517543",
"161750625450884"
] | [
"nonn",
"nice"
] | 31 | 0 | 2 | [
"A000571",
"A007747",
"A047730",
"A064422",
"A064626"
] | null | P. Di Francesco (philippe(AT)amoco.saclay.cea.fr), N. J. A. Sloane | 2023-07-08T19:24:25 | oeisdata/seq/A007/A007747.seq | 22c64f102a763367370e95bad42ecec0 |
A007748 | Number of self-converse oriented trees with n nodes. | [
"1",
"1",
"1",
"2",
"3",
"7",
"10",
"26",
"39",
"107",
"160",
"458",
"702",
"2058",
"3177",
"9498",
"14830",
"44947",
"70678",
"216598",
"342860",
"1059952",
"1686486",
"5251806",
"8393681",
"26297238",
"42187148",
"132856766",
"213828802",
"676398395",
"1091711076"
] | [
"nonn",
"nice"
] | 24 | 1 | 4 | [
"A000238",
"A007748"
] | null | N. J. A. Sloane | 2021-12-16T22:18:38 | oeisdata/seq/A007/A007748.seq | 3fbabc8c02eddd6c3c824a3dcf5dc225 |
A007749 | Numbers k such that k!! - 1 is prime. | [
"3",
"4",
"6",
"8",
"16",
"26",
"64",
"82",
"90",
"118",
"194",
"214",
"728",
"842",
"888",
"2328",
"3326",
"6404",
"8670",
"9682",
"27056",
"44318",
"76190",
"100654",
"145706"
] | [
"nonn",
"hard",
"nice"
] | 63 | 1 | 1 | [
"A006882",
"A007749",
"A091415",
"A117141"
] | null | N. J. A. Sloane | 2025-03-19T08:24:52 | oeisdata/seq/A007/A007749.seq | 2cb396aee0dbdea2d7ae6d94caef6c35 |
A007750 | Nonnegative integers n such that n^2*(n+1)*(2*n+1)^2*(7*n+1)/36 is a square. | [
"0",
"1",
"7",
"24",
"120",
"391",
"1921",
"6240",
"30624",
"99457",
"488071",
"1585080",
"7778520",
"25261831",
"123968257",
"402604224",
"1975713600",
"6416405761",
"31487449351",
"102259887960",
"501823476024",
"1629741801607",
"7997688167041",
"25973608937760"
] | [
"nonn",
"easy"
] | 37 | 0 | 3 | [
"A007750",
"A007751",
"A007752",
"A077412"
] | null | John C. Hallyburton, Jr. (hallyb(AT)vmsdev.enet.dec.com) | 2024-12-29T16:10:42 | oeisdata/seq/A007/A007750.seq | bce520fe8c1eb81558f26fd295e2f87d |
A007751 | Even bisection of A007750. | [
"0",
"7",
"120",
"1921",
"30624",
"488071",
"7778520",
"123968257",
"1975713600",
"31487449351",
"501823476024",
"7997688167041",
"127461187196640",
"2031381306979207",
"32374639724470680",
"515962854284551681",
"8223031028828356224"
] | [
"nonn"
] | 26 | 0 | 2 | [
"A007750",
"A007751",
"A007752",
"A077412"
] | null | John C. Hallyburton, Jr. (hallyb(AT)vmsdev.enet.dec.com) | 2023-12-30T10:56:55 | oeisdata/seq/A007/A007751.seq | adb62f4c2333d9a9cad518496b1e619d |
A007752 | Odd bisection of A007750. | [
"1",
"24",
"391",
"6240",
"99457",
"1585080",
"25261831",
"402604224",
"6416405761",
"102259887960",
"1629741801607",
"25973608937760",
"413948001202561",
"6597194410303224",
"105141162563649031",
"1675661406608081280"
] | [
"nonn",
"easy"
] | 23 | 1 | 2 | [
"A007750",
"A007751",
"A007752"
] | null | John C. Hallyburton, Jr. (hallyb(AT)vmsdev.enet.dec.com) | 2024-07-04T14:33:15 | oeisdata/seq/A007/A007752.seq | a0240f05bbd8651b712b9db36648067c |
A007753 | a(n) = Sum_{k=0..n-1} binomial(a(k)^2, k). | [
"1",
"1",
"2",
"8",
"41672",
"378916495683075745757412513402693048"
] | [
"easy",
"nonn"
] | 16 | 0 | 3 | null | null | Barry Brunson (bbrunson(AT)wku.edu) | 2021-06-11T20:50:26 | oeisdata/seq/A007/A007753.seq | e210229b22b1ef84e883c79150fb4620 |
A007754 | Array (a frieze pattern) defined by a(n,k) = (a(n-1,k)*a(n-1,k+1) - 1) / a(n-2,k+1), read by antidiagonals. | [
"1",
"1",
"1",
"1",
"2",
"1",
"1",
"3",
"5",
"2",
"1",
"4",
"11",
"18",
"7",
"1",
"5",
"19",
"52",
"85",
"33",
"1",
"6",
"29",
"110",
"301",
"492",
"191",
"1",
"7",
"41",
"198",
"751",
"2055",
"3359",
"1304",
"1",
"8",
"55",
"322",
"1555",
"5898",
"16139",
"26380",
"10241",
"1",
"9",
"71",
"488",
"2857",
"13797",
"52331",
"143196",
"234061",
"90865",
"1",
"10",
"89",
"702"
] | [
"nonn",
"easy",
"nice",
"tabl"
] | 33 | 0 | 5 | [
"A000012",
"A000027",
"A007754",
"A028387",
"A058794",
"A058796",
"A058797",
"A058799",
"A099933"
] | null | N. J. A. Sloane, Nov 28 2000 | 2023-06-06T05:05:58 | oeisdata/seq/A007/A007754.seq | cef56ac6081788ade406042c0259add7 |
A007755 | Smallest number m such that the trajectory of m under iteration of Euler's totient function phi(n) [A000010] contains exactly n distinct numbers, including m and the fixed point. | [
"1",
"2",
"3",
"5",
"11",
"17",
"41",
"83",
"137",
"257",
"641",
"1097",
"2329",
"4369",
"10537",
"17477",
"35209",
"65537",
"140417",
"281929",
"557057",
"1114129",
"2384897",
"4227137",
"8978569",
"16843009",
"35946497",
"71304257",
"143163649",
"286331153",
"541073537",
"1086374209",
"2281701377",
"4295098369"
] | [
"nonn",
"nice"
] | 49 | 1 | 2 | [
"A000010",
"A003434",
"A007755",
"A049108",
"A060611",
"A092873",
"A098196",
"A227946"
] | null | Pepijn van Erp [ vanerp(AT)sci.kun.nl ] | 2019-03-26T23:41:00 | oeisdata/seq/A007/A007755.seq | 47a869a760d1327dd1172f915ab8fd86 |
A007756 | Number of irreducible indecomposable spherical curves with n crossings (only ordinary double points), the circle is oriented, the sphere is not oriented (OU case). | [
"0",
"0",
"1",
"1",
"2",
"3",
"11",
"38",
"156",
"638",
"2973",
"13882",
"67868",
"338147",
"1720303",
"8905996",
"46774728",
"248918004",
"1340083514",
"7288922610",
"40019870539",
"221582395052",
"1236358849827"
] | [
"nonn",
"more"
] | 34 | 1 | 5 | [
"A007756",
"A008986",
"A008987",
"A008988",
"A008989",
"A264759",
"A264760",
"A264761"
] | null | Jean Betrema | 2024-03-30T12:15:08 | oeisdata/seq/A007/A007756.seq | 3fadbc8582f3afadbe01d332c5a2ecc7 |
A007757 | Dwork-Kontsevich sequence evaluated at 2*n. | [
"1",
"2",
"36",
"144",
"1440",
"17280",
"241920",
"29030400",
"1567641600",
"156764160000",
"217275125760000",
"1738201006080000",
"45193226158080000",
"3796230997278720000",
"113886929918361600000",
"1822190878693785600000",
"22489479824838701875200000",
"28336744579296764362752000000",
"1076796294013277045784576000000",
"1679802218660712191423938560000000"
] | [
"nonn"
] | 35 | 1 | 2 | [
"A007757",
"A056612",
"A131657",
"A131658"
] | null | Richard E. Borcherds (reb(AT)math.berkeley.edu) | 2020-05-24T02:46:03 | oeisdata/seq/A007/A007757.seq | 3e89877dd825f66ecf20a4c9ce9b142b |
A007758 | a(n) = 2^n*n^2. | [
"0",
"2",
"16",
"72",
"256",
"800",
"2304",
"6272",
"16384",
"41472",
"102400",
"247808",
"589824",
"1384448",
"3211264",
"7372800",
"16777216",
"37879808",
"84934656",
"189267968",
"419430400",
"924844032",
"2030043136",
"4437573632",
"9663676416",
"20971520000",
"45365592064",
"97844723712",
"210453397504"
] | [
"nonn",
"easy"
] | 60 | 0 | 2 | [
"A007758",
"A014477",
"A248917",
"A355234"
] | null | David J. Snook (ua532(AT)freenet.victoria.bc.ca) | 2022-06-28T10:59:22 | oeisdata/seq/A007/A007758.seq | 6c959b4dc86679369edbf3fbb632e744 |
A007759 | Knopfmacher expansion of sqrt(2): a(2n) = 2*(a(2n-1) + 1)^2 - 1, a(2n+1) = 2*(a(2n)^2 - 1). | [
"2",
"17",
"576",
"665857",
"886731088896",
"1572584048032918633353217",
"4946041176255201878775086487573351061418968498176",
"48926646634423881954586808839856694558492182258668537145547700898547222910968507268117381704646657"
] | [
"nonn"
] | 19 | 1 | 1 | [
"A001601",
"A002193",
"A007759"
] | null | Arnold Knopfmacher | 2022-09-08T08:44:35 | oeisdata/seq/A007/A007759.seq | 0886a93d9d3e80dd3e856dbcb6ad34bb |
A007760 | Number of solid partitions of height n in a cube of side n. | [
"1",
"2",
"168",
"17792748",
"75241806496951632"
] | [
"nonn",
"hard",
"more"
] | 8 | 0 | 2 | null | null | destain(AT)clipper.ens.fr (Nicolas DESTAINVILLE) | 2017-08-20T21:40:18 | oeisdata/seq/A007/A007760.seq | 708c64ca5b2e66b967b08bb20002d535 |
A007761 | (n+1) * a(n+1) - 2 (68*n^2+68*n+27) * a(n) + 6 * n * (772*n^2+35) * a(n-1) - 2 * (2*n-1)^2 * (68*n^2-68*n+27) * a(n-2) + (2*n-1)^2 * (n-1) * (2*n-3)^2 * a(n-3) = 0. | [
"1",
"54",
"6381",
"1176900",
"295843509",
"94263721650",
"36391089828249",
"16506884910849480",
"8603605199199386025",
"5066519768097762780270",
"3326644994941284848273925",
"2409605195467508091244871820"
] | [
"nonn"
] | 22 | 0 | 2 | null | null | Bruno Haible | 2020-03-04T16:28:23 | oeisdata/seq/A007/A007761.seq | fb72b8c260861cd512a34f77e7298870 |
A007762 | Number of domino tilings of a certain region. | [
"1",
"8",
"120",
"2288",
"49680",
"1170968",
"29206632",
"759265760",
"20371816992",
"560386232744"
] | [
"nonn",
"unkn",
"more"
] | 22 | 1 | 2 | null | null | James Propp | 2021-11-19T02:47:58 | oeisdata/seq/A007/A007762.seq | d9f70632e8fccff9b21194d6b69857e5 |
A007763 | Number of pairs of length n permutations achievable by double-ended priority queue. | [
"1",
"4",
"32",
"392",
"6488",
"135360",
"3408120",
"100520432",
"3398723928",
"129588803696",
"5500585388616",
"257232445666832"
] | [
"nonn",
"more"
] | 16 | 1 | 2 | [
"A000272",
"A007763"
] | null | mda(AT)cs.st-andrews.ac.uk (Michael Atkinson) | 2024-06-19T18:58:47 | oeisdata/seq/A007/A007763.seq | 1030a80bea15928479d9a75e3dd831df |
A007764 | Number of nonintersecting (or self-avoiding) rook paths joining opposite corners of an n X n grid. | [
"1",
"2",
"12",
"184",
"8512",
"1262816",
"575780564",
"789360053252",
"3266598486981642",
"41044208702632496804",
"1568758030464750013214100",
"182413291514248049241470885236",
"64528039343270018963357185158482118",
"69450664761521361664274701548907358996488"
] | [
"nonn",
"walk",
"hard",
"nice",
"changed"
] | 143 | 1 | 2 | [
"A000532",
"A001184",
"A007764",
"A064297",
"A064298",
"A271507"
] | null | David Radcliffe and Don Knuth | 2025-04-16T10:56:41 | oeisdata/seq/A007/A007764.seq | ace17119797fe9335472ba473a21370a |
A007765 | Primes p == 1 (mod 8), p = a^2 +64*b^2 such that y^2 = x^3 + p*x has rank 0. | [
"257",
"577",
"1097",
"1201",
"1217",
"1481",
"1721",
"2441",
"2657",
"2833",
"2857",
"3121",
"3449",
"3761",
"4001",
"4057",
"4177",
"4217",
"4297",
"4409",
"4481",
"4657",
"4721",
"4817",
"4937",
"5297",
"5569",
"5737",
"6121",
"6481",
"6521",
"6793",
"6841",
"6857",
"7121",
"7129",
"7793",
"7817",
"7841",
"8081",
"8161",
"8761"
] | [
"nonn"
] | 12 | 1 | 1 | [
"A007765",
"A007766"
] | null | H. E Rose [ H.E.Rose(AT)bristol.ac.uk ] | 2018-01-09T17:55:17 | oeisdata/seq/A007/A007765.seq | 13fe0432dce3d1ed895b835116e8c508 |
A007766 | Primes p == 1 (mod 8), p = a^2 + 64*b^2 such that y^2 = x^3 + p*x has rank 2. | [
"73",
"89",
"113",
"233",
"281",
"337",
"353",
"593",
"601",
"617",
"881",
"937",
"1033",
"1049",
"1153",
"1193",
"1249",
"1289",
"1433",
"1553",
"1601",
"1609",
"1753",
"1777",
"1801",
"1889",
"1913",
"2089",
"2113",
"2129",
"2273",
"2281",
"2393",
"2473",
"2593",
"2689",
"2969",
"3049",
"3089",
"3137",
"3217",
"3257",
"3313",
"3361",
"3529"
] | [
"nonn"
] | 8 | 1 | 1 | [
"A007765",
"A007766"
] | null | H. E Rose [ H.E.Rose(AT)bristol.ac.uk ] | 2017-10-12T08:23:03 | oeisdata/seq/A007/A007766.seq | 56d0f7eb94f6cfe43d39f14323c7770c |
A007767 | Number of pairs of permutations of degree n that avoid (12,21). | [
"1",
"1",
"3",
"17",
"151",
"1899",
"31711",
"672697",
"17551323",
"549500451",
"20246665349",
"864261579999",
"42190730051687",
"2329965898878307",
"144220683681814515",
"9926440976428215117",
"754465679498026783923",
"62939664181821196179459",
"5732069150321309755351161",
"567176164248814234096702451"
] | [
"nonn"
] | 83 | 0 | 3 | [
"A000260",
"A007767",
"A263754"
] | null | Steve Linton | 2025-01-02T22:20:08 | oeisdata/seq/A007/A007767.seq | e0ba636f4fc74fc75f35d70310604a8a |
A007768 | From Engel product expansion of 4/7. | [
"3",
"3",
"4",
"4",
"6",
"17",
"36",
"44",
"49",
"74",
"122",
"126",
"744",
"7814",
"9238",
"9432",
"52114",
"33241100",
"85747623",
"353210861",
"355051655",
"1950030118",
"32235431345",
"50590143817",
"58937626393",
"482819610949",
"1515905452711",
"2679281166868",
"25090147463646",
"207012319502700"
] | [
"nonn"
] | 14 | 1 | 1 | null | null | Arnold Knopfmacher | 2018-01-24T03:35:14 | oeisdata/seq/A007/A007768.seq | 631ebc81f3055a30ab58af4d156ba170 |
A007769 | Number of chord diagrams with n chords; number of pairings on a necklace. | [
"1",
"1",
"2",
"5",
"18",
"105",
"902",
"9749",
"127072",
"1915951",
"32743182",
"624999093",
"13176573910",
"304072048265",
"7623505722158",
"206342800616597",
"5996837126024824",
"186254702826289089",
"6156752656678674792",
"215810382466145354405",
"7995774669504366055054"
] | [
"nonn",
"easy",
"nice"
] | 71 | 0 | 3 | [
"A007769",
"A054499",
"A104255",
"A279207",
"A279208"
] | null | Jean.Betrema(AT)labri.u-bordeaux.fr | 2019-04-30T09:54:22 | oeisdata/seq/A007/A007769.seq | 9bfe83b2b261182b3f63c251323477de |
A007770 | Happy numbers: numbers whose trajectory under iteration of sum of squares of digits map (see A003132) includes 1. | [
"1",
"7",
"10",
"13",
"19",
"23",
"28",
"31",
"32",
"44",
"49",
"68",
"70",
"79",
"82",
"86",
"91",
"94",
"97",
"100",
"103",
"109",
"129",
"130",
"133",
"139",
"167",
"176",
"188",
"190",
"192",
"193",
"203",
"208",
"219",
"226",
"230",
"236",
"239",
"262",
"263",
"280",
"291",
"293",
"301",
"302",
"310",
"313",
"319",
"320",
"326",
"329",
"331",
"338"
] | [
"nonn",
"base",
"nice",
"easy"
] | 129 | 1 | 2 | [
"A001273",
"A002025",
"A003132",
"A007770",
"A031177",
"A035497",
"A035502",
"A046519",
"A050972",
"A050973",
"A068571",
"A072494",
"A074902",
"A090425",
"A103369",
"A124095",
"A219667",
"A239320",
"A240849"
] | null | N. J. A. Sloane, A.R.McKenzie(AT)bnr.co.uk | 2025-02-16T08:32:31 | oeisdata/seq/A007/A007770.seq | 9fdc87b40e678920eb4b4333591f34f0 |
A007771 | Values of Ehrhart polynomial of dilation by 2 of Relaxed Boolean Quadric Polytope of order 4. | [
"1",
"224",
"10473",
"173760",
"1569465",
"9559392",
"44220785",
"167026432",
"540036369",
"1544011360"
] | [
"nonn"
] | 3 | 0 | 2 | null | null | Einar Steingrimsson [ einar(AT)math.chalmers.se ] | 2003-05-16T03:00:00 | oeisdata/seq/A007/A007771.seq | f8bbf7b1c1413af67ed75af7786325c0 |
A007772 | Values of Ehrhart polynomial of dilation by 2 of Relaxed Boolean Quadric Polytope of order 3. | [
"1",
"40",
"417",
"2272",
"8545",
"25320",
"63553"
] | [
"nonn"
] | 3 | 0 | 2 | null | null | Einar Steingrimsson [ einar(AT)math.chalmers.se ] | 2003-05-16T03:00:00 | oeisdata/seq/A007/A007772.seq | 2417887486b89bf0636e42b61c9cf95e |
A007773 | For any circular arrangement of 0..n-1, let S = sum of squares of every sum of two contiguous numbers; then a(n) = # of distinct values of S. | [
"1",
"1",
"1",
"3",
"8",
"21",
"43",
"69",
"102",
"145",
"197",
"261",
"336",
"425",
"527",
"645",
"778",
"929",
"1097",
"1285",
"1492",
"1721",
"1971",
"2245",
"2542",
"2865",
"3213",
"3589",
"3992",
"4425",
"4887",
"5381",
"5906",
"6465",
"7057",
"7685",
"8348",
"9049",
"9787",
"10565",
"11382",
"12241",
"13141",
"14085",
"15072",
"16105"
] | [
"nonn",
"easy"
] | 27 | 1 | 4 | null | null | K. S. Brown (kevin2003(AT)delphi.com), Hugh L. Montgomery | 2022-09-08T08:44:35 | oeisdata/seq/A007/A007773.seq | 040b2cbdf806e46b0f9d68d8f8000b80 |
A007774 | Numbers that are divisible by exactly 2 different primes; numbers n with omega(n) = A001221(n) = 2. | [
"6",
"10",
"12",
"14",
"15",
"18",
"20",
"21",
"22",
"24",
"26",
"28",
"33",
"34",
"35",
"36",
"38",
"39",
"40",
"44",
"45",
"46",
"48",
"50",
"51",
"52",
"54",
"55",
"56",
"57",
"58",
"62",
"63",
"65",
"68",
"69",
"72",
"74",
"75",
"76",
"77",
"80",
"82",
"85",
"86",
"87",
"88",
"91",
"92",
"93",
"94",
"95",
"96",
"98",
"99",
"100",
"104",
"106",
"108",
"111",
"112",
"115",
"116",
"117",
"118"
] | [
"nonn"
] | 69 | 1 | 1 | [
"A000040",
"A001358",
"A006881",
"A007774",
"A014612",
"A014613",
"A014614",
"A046386",
"A046387",
"A067885",
"A085736",
"A112801",
"A125666",
"A256617"
] | null | Luke Pebody (ltp1000(AT)hermes.cam.ac.uk) | 2024-04-14T03:49:31 | oeisdata/seq/A007/A007774.seq | eac3277a599152d603c1577744f97bb9 |
A007775 | Numbers not divisible by 2, 3 or 5. | [
"1",
"7",
"11",
"13",
"17",
"19",
"23",
"29",
"31",
"37",
"41",
"43",
"47",
"49",
"53",
"59",
"61",
"67",
"71",
"73",
"77",
"79",
"83",
"89",
"91",
"97",
"101",
"103",
"107",
"109",
"113",
"119",
"121",
"127",
"131",
"133",
"137",
"139",
"143",
"149",
"151",
"157",
"161",
"163",
"167",
"169",
"173",
"179",
"181",
"187",
"191",
"193",
"197",
"199",
"203",
"209"
] | [
"nonn",
"easy"
] | 187 | 1 | 2 | [
"A000027",
"A000538",
"A005408",
"A007310",
"A007775",
"A008364",
"A008365",
"A008366",
"A054403",
"A080671",
"A145011",
"A166061",
"A166063",
"A227896"
] | null | N. J. A. Sloane | 2025-02-16T08:32:31 | oeisdata/seq/A007/A007775.seq | ed0b70e1fe9d2a102e1138d2eb1018d7 |
A007776 | Number of connected posets with n elements of height 1. | [
"1",
"2",
"4",
"10",
"27",
"88",
"328",
"1460",
"7799",
"51196",
"422521",
"4483460",
"62330116",
"1150504224",
"28434624153",
"945480850638",
"42417674401330",
"2572198227615998",
"211135833162079184",
"23487811567341121158",
"3545543330739039981738",
"727053904070651775719646"
] | [
"nonn"
] | 40 | 2 | 2 | [
"A002031",
"A005142",
"A007776",
"A048194",
"A049312",
"A055192",
"A318870",
"A342500"
] | null | Georg Wambach (gw(AT)informatik.Uni-Koeln.de) | 2023-11-29T11:42:04 | oeisdata/seq/A007/A007776.seq | d6b737b9e2460c273a78170137a6bff4 |
A007777 | Number of overlap-free binary words of length n. | [
"1",
"2",
"4",
"6",
"10",
"14",
"20",
"24",
"30",
"36",
"44",
"48",
"60",
"60",
"62",
"72",
"82",
"88",
"96",
"112",
"120",
"120",
"136",
"148",
"164",
"152",
"154",
"148",
"162",
"176",
"190",
"196",
"210",
"216",
"224",
"228",
"248",
"272",
"284",
"296",
"300",
"296",
"320",
"332",
"356",
"356",
"376",
"400",
"416",
"380",
"382",
"376",
"382",
"356",
"374",
"392",
"410"
] | [
"nonn",
"easy",
"nice"
] | 52 | 0 | 2 | [
"A007777",
"A028445",
"A038952",
"A082379",
"A082380"
] | null | Julien Cassaigne (cassaign(AT)clipper.ens.fr) | 2025-02-16T08:32:31 | oeisdata/seq/A007/A007777.seq | edbd405a6c91ef25e49e5682138127a7 |
A007778 | a(n) = n^(n+1). | [
"0",
"1",
"8",
"81",
"1024",
"15625",
"279936",
"5764801",
"134217728",
"3486784401",
"100000000000",
"3138428376721",
"106993205379072",
"3937376385699289",
"155568095557812224",
"6568408355712890625",
"295147905179352825856",
"14063084452067724991009",
"708235345355337676357632"
] | [
"nonn",
"easy"
] | 79 | 0 | 3 | [
"A000169",
"A000272",
"A000312",
"A007778",
"A007830",
"A008785",
"A008786",
"A008787",
"A008788",
"A008789",
"A008790",
"A008791",
"A061250",
"A065440",
"A135608",
"A143857"
] | null | N. J. A. Sloane | 2025-02-18T14:26:45 | oeisdata/seq/A007/A007778.seq | f50eb361dce7fb0f2b180485a4b618ab |
A007779 | Coefficients of asymptotic expansion of Ramanujan false theta series. | [
"1",
"1",
"1",
"2",
"5",
"17",
"72",
"367",
"2179",
"14750",
"112023",
"942879",
"8708912",
"87563937",
"951933849",
"11125383714",
"139092236301",
"1852257089937",
"26173848663000",
"391153031777263",
"6163682285356171",
"102136840106457790",
"1775499429402739247",
"32307194057014483391"
] | [
"nonn",
"nice",
"easy"
] | 27 | 0 | 4 | [
"A000111",
"A007779",
"A115455"
] | null | William F. Galway (galway(AT)math.uiuc.edu) | 2024-08-03T07:10:20 | oeisdata/seq/A007/A007779.seq | 2c1ec7815a2d8ac52dbe6795708c7cfc |
A007780 | Losing initial configurations in 2-hole Tchuka Ruma. | [
"1",
"2",
"3",
"6",
"9",
"11",
"18",
"20",
"27",
"30",
"54",
"81",
"162",
"168",
"243",
"486",
"729",
"1458",
"2187",
"4374",
"6561",
"13122",
"19683",
"39366",
"59049",
"118098",
"177147",
"354294",
"531441",
"1062882",
"1594323",
"3188646",
"4782969",
"9565938",
"14348907",
"28697814",
"43046721",
"86093442"
] | [
"nonn"
] | 20 | 1 | 2 | null | null | Darrah Chavey | 2018-01-25T14:09:38 | oeisdata/seq/A007/A007780.seq | ae5c817b2821a4a7bd2a6652d1c36b3b |
A007781 | a(n) = (n+1)^(n+1) - n^n for n>0, a(0) = 1. | [
"1",
"3",
"23",
"229",
"2869",
"43531",
"776887",
"15953673",
"370643273",
"9612579511",
"275311670611",
"8630788777645",
"293959006143997",
"10809131718965763",
"426781883555301359",
"18008850183328692241",
"808793517812627212561"
] | [
"nonn",
"easy"
] | 53 | 0 | 2 | [
"A000312",
"A002407",
"A003215",
"A007781",
"A068146",
"A068954",
"A068955",
"A068956",
"A068957",
"A127854"
] | null | Peter McCormack (peter.mccormack(AT)its.csiro.au) | 2025-02-16T08:32:31 | oeisdata/seq/A007/A007781.seq | 965d40b1b9ff7b52351564aa1cb715da |
A007782 | Number of factors in the infinite word formed by the Kolakoski sequence A000002. | [
"1",
"2",
"4",
"6",
"10",
"14",
"18",
"26",
"34",
"42",
"50",
"62",
"78",
"94",
"110",
"126",
"142",
"162",
"186",
"218",
"250",
"282",
"314",
"346",
"378",
"410",
"446",
"486",
"534",
"590",
"654",
"718",
"782",
"846",
"910",
"974",
"1038",
"1102",
"1166",
"1234",
"1302",
"1378",
"1458",
"1554",
"1658",
"1774",
"1898",
"2026",
"2154",
"2282",
"2410",
"2538",
"2666"
] | [
"nonn",
"nice"
] | 17 | 0 | 2 | [
"A000002",
"A007782"
] | null | Patricia Lamas (lamas(AT)math.uqam.ca) | 2015-02-04T15:46:34 | oeisdata/seq/A007/A007782.seq | 42d2822c404ac03c69b87285567ede87 |
A007783 | Mixed Van der Waerden numbers w(n, 3; 2). | [
"3",
"6",
"9",
"18",
"22",
"32",
"46",
"58",
"77",
"97",
"114",
"135",
"160",
"186",
"218",
"238",
"279",
"312",
"349"
] | [
"nonn",
"hard",
"more"
] | 27 | 1 | 1 | [
"A002886",
"A007783"
] | null | Matthew Klimesh (matthew(AT)engin.umich.edu) | 2024-08-03T05:43:31 | oeisdata/seq/A007/A007783.seq | f43462f3783f577f58892a31ba414643 |
A007784 | Van der Waerden numbers W(4,n). | [
"4",
"8",
"18",
"35",
"55",
"73",
"109",
"146",
"309"
] | [
"nonn",
"hard",
"more"
] | 11 | 1 | 1 | null | null | Matthew Klimesh (matthew(AT)engin.umich.edu) | 2018-05-13T08:54:17 | oeisdata/seq/A007/A007784.seq | f1d94e4ce9f36ace60fb773b0dcf5a08 |
A007785 | Number of sets of positive integers <= n^2 whose sum is (n^3 + n)/2. | [
"1",
"1",
"2",
"17",
"306",
"10828",
"654857",
"63019177",
"9183937890",
"1953896126383",
"589909767142505",
"247074213707554144",
"140902072248206260266",
"107704589610917073318533",
"108877374411946899963718973",
"143864444783939220165210185294",
"245934054410000090878614435736720"
] | [
"nonn"
] | 28 | 0 | 3 | [
"A007785",
"A052456"
] | null | Hidetoshi MINO [ mino(AT)hep.esb.yamanashi.ac.jp, mino(AT)mino.scri.fsu.edu ] | 2022-05-20T05:17:20 | oeisdata/seq/A007/A007785.seq | a6cb224d80e200189d536f4825d30344 |
A007786 | Number of nonintersecting rook paths joining opposite corners of 4 X n board. | [
"1",
"8",
"38",
"184",
"976",
"5382",
"29739",
"163496",
"896476",
"4913258",
"26932712",
"147657866",
"809563548",
"4438573234",
"24335048679",
"133419610132",
"731487691902",
"4010463268476",
"21987818897998",
"120550710615560",
"660932932108467"
] | [
"nonn",
"easy",
"nice",
"walk"
] | 28 | 1 | 2 | [
"A006192",
"A007764",
"A007786",
"A007787",
"A064298"
] | null | Heiner Marxen | 2024-02-07T09:36:36 | oeisdata/seq/A007/A007786.seq | 870906a4f0021967289728d86483bbd2 |
A007787 | Number of nonintersecting rook paths joining opposite corners of 5 X n board. | [
"1",
"16",
"125",
"976",
"8512",
"79384",
"752061",
"7110272",
"67005561",
"630588698",
"5933085772",
"55827318685",
"525343024814",
"4943673540576",
"46521924780255",
"437788749723725",
"4119750109152730",
"38768318191017931",
"364823700357765771",
"3433121323699285343"
] | [
"nonn",
"walk"
] | 26 | 1 | 2 | [
"A007764",
"A007786",
"A007787",
"A064298"
] | null | Heiner Marxen | 2020-04-06T06:29:11 | oeisdata/seq/A007/A007787.seq | e0a79c494a3c67decb2ff0ac5631f133 |
A007788 | Number of augmented Andre 3-signed permutations: E.g.f. (1-sin(3*x))^(-1/3). | [
"1",
"1",
"4",
"19",
"136",
"1201",
"13024",
"165619",
"2425216",
"40132801",
"740882944",
"15091932019",
"336257744896",
"8134269015601",
"212309523595264",
"5946914908771219",
"177934946000306176",
"5663754614516217601"
] | [
"nonn"
] | 31 | 0 | 3 | [
"A007788",
"A007863",
"A235132",
"A235135"
] | null | R. Ehrenborg (ehrenbor(AT)lacim.uqam.ca) and M. A. Readdy (readdy(AT)lacim.uqam.ca) | 2022-09-08T08:44:35 | oeisdata/seq/A007/A007788.seq | 0bc84372ceff9f3540b8201b1f109b7b |
A007789 | From a problem concerning circulant matrices and Gauss sums. | [
"1",
"1",
"0",
"4",
"1",
"0",
"13",
"4",
"27",
"1",
"1",
"0",
"25",
"13",
"0",
"16",
"1",
"27",
"37",
"4",
"0",
"1",
"1",
"0",
"25",
"25",
"81",
"52",
"1",
"0",
"61",
"16",
"0",
"1",
"13",
"108",
"73",
"37",
"0",
"4",
"1",
"0",
"85",
"4",
"27",
"1",
"1",
"0",
"133",
"25",
"0",
"100",
"1",
"81",
"1",
"52",
"0",
"1",
"1",
"0",
"121",
"61"
] | [
"nonn",
"more"
] | 28 | 0 | 4 | [
"A007789",
"A007790",
"A007791",
"A007792"
] | null | Zoltan Reti | 2024-11-19T16:32:36 | oeisdata/seq/A007/A007789.seq | a001c4bf2324ae347d7259d56eeb8cc1 |
A007790 | From a problem concerning circulant matrices and Gauss sums. | [
"1",
"0",
"11",
"32",
"61",
"0",
"55",
"256",
"153",
"0",
"131",
"352",
"469",
"0",
"671",
"2048",
"817",
"0"
] | [
"nonn",
"more"
] | 21 | 0 | 3 | [
"A007789",
"A007790",
"A007791",
"A007792"
] | null | Zoltan Reti | 2024-11-19T16:31:41 | oeisdata/seq/A007/A007790.seq | 14f3974f22b46ec830571292be0f092c |
A007791 | From a problem concerning circulant matrices and Gauss sums. | [
"1",
"1",
"1",
"16",
"0",
"1",
"1",
"256",
"81",
"0",
"4641",
"16",
"1",
"1",
"0",
"4096",
"1",
"81",
"721",
"0",
"1",
"4641",
"1",
"256",
"78125",
"1",
"6561",
"16"
] | [
"nonn",
"more"
] | 19 | 0 | 4 | [
"A007789",
"A007790",
"A007791",
"A007792"
] | null | Zoltan Reti | 2024-11-19T16:31:34 | oeisdata/seq/A007/A007791.seq | c45e59a5499724bb54b1006b8e7ac291 |
A007792 | From a problem concerning circulant matrices and Gauss sums. | [
"1",
"8",
"81",
"640",
"821",
"648",
"9031",
"14336",
"32805",
"6568",
"17051",
"51840",
"122461",
"72248",
"66501",
"360448",
"92753",
"262440",
"586531"
] | [
"nonn",
"more"
] | 18 | 0 | 2 | [
"A007789",
"A007790",
"A007791",
"A007792"
] | null | Zoltan Reti | 2024-11-19T16:32:15 | oeisdata/seq/A007/A007792.seq | b17089ac496913fc9be67cf492f652e7 |
A007793 | Number of conjugacy classes of compact Cartan subgroups in Sp_{2n}(F), where p>n and the p-adic field F contains all r-th roots of unity for all r <= 2n. | [
"6",
"39",
"188",
"861",
"3510",
"13623",
"49524",
"172893",
"577728",
"1868109",
"5847054",
"17814077",
"52890972",
"153535575",
"436304266",
"1216282521",
"3329926392",
"8966547362",
"23769745656",
"62101564899",
"160033141790",
"407108557269"
] | [
"nonn"
] | 4 | 1 | 1 | null | null | Jeff Adler (adler(AT)uakron.edu) | 2004-06-12T03:00:00 | oeisdata/seq/A007/A007793.seq | 7e5b10def3e21c96c3e41a28e94d2ff8 |
A007794 | Juxtapose pairs of primes (starting at 1). | [
"12",
"35",
"711",
"1317",
"1923",
"2931",
"3741",
"4347",
"5359",
"6167",
"7173",
"7983",
"8997",
"101103",
"107109",
"113127",
"131137",
"139149",
"151157",
"163167",
"173179",
"181191",
"193197",
"199211",
"223227",
"229233"
] | [
"nonn",
"base"
] | 10 | 1 | 1 | null | null | bmoore(AT)artemis.ess.ucla.edu (William B. Moore) | 2019-07-12T14:00:13 | oeisdata/seq/A007/A007794.seq | a63685ec0c0d5f50ac742dc51df36693 |
A007795 | Juxtapose pairs of primes. | [
"23",
"57",
"1113",
"1719",
"2329",
"3137",
"4143",
"4753",
"5961",
"6771",
"7379",
"8389",
"97101",
"103107",
"109113",
"127131",
"137139",
"149151",
"157163",
"167173",
"179181",
"191193",
"197199",
"211223",
"227229",
"233239",
"241251",
"257263",
"269271",
"277281",
"283293",
"307311",
"313317",
"331337",
"347349",
"353359"
] | [
"nonn",
"base"
] | 19 | 1 | 1 | null | null | William B. Moore (bmoore(AT)artemis.ess.ucla.edu) | 2022-09-08T08:44:35 | oeisdata/seq/A007/A007795.seq | 7d553a92948a32cb249725d3d830a3ef |
A007796 | List of pairs of primes in reverse order, starting at 1. | [
"21",
"53",
"117",
"1713",
"2319",
"3129",
"4137",
"4743",
"5953",
"6761",
"7371",
"8379",
"9789",
"103101",
"109107",
"127113",
"137131",
"149139",
"157151",
"167163",
"179173",
"191181",
"197193",
"211199",
"227223"
] | [
"nonn",
"base"
] | 11 | 1 | 1 | null | null | bmoore(AT)artemis.ess.ucla.edu (William B. Moore) | 2015-05-10T15:43:21 | oeisdata/seq/A007/A007796.seq | 38ee85705e3f4369794ffecc6cdb72d7 |
A007797 | List of pairs of primes in reverse order. | [
"32",
"75",
"1311",
"1917",
"2923",
"3731",
"4341",
"5347",
"6159",
"7167",
"7973",
"8983",
"10197",
"107103",
"113109",
"131127",
"139137",
"151149",
"163157",
"173167",
"181179",
"193191",
"199197",
"223211",
"229227",
"239233",
"251241",
"263257",
"271269",
"281277",
"293283",
"311307",
"317313",
"337331",
"349347",
"359353"
] | [
"nonn",
"base"
] | 11 | 1 | 1 | [
"A007795",
"A007797"
] | null | William B. Moore (bmoore(AT)artemis.ess.ucla.edu) | 2022-09-08T08:44:35 | oeisdata/seq/A007/A007797.seq | 3ce5cc44c233447d73bdecb7092c2dc0 |
A007798 | Expected number of random moves in Tower of Hanoi problem with n disks starting with a randomly chosen position and ending at a position with all disks on the same peg. | [
"0",
"0",
"2",
"18",
"116",
"660",
"3542",
"18438",
"94376",
"478440",
"2411882",
"12118458",
"60769436",
"304378620",
"1523487422",
"7622220078",
"38125449296",
"190670293200",
"953480606162",
"4767790451298",
"23840114517956",
"119204059374180",
"596030757224102",
"2980185167180118",
"14901019979079416"
] | [
"nonn",
"easy"
] | 39 | 0 | 3 | [
"A005058",
"A007798",
"A134939"
] | null | David G. Poole (dpoole(AT)trentu.ca) | 2022-09-08T08:44:35 | oeisdata/seq/A007/A007798.seq | bd28f99852e575f7130ef6d96088bdea |
A007799 | Irregular triangle read by rows: Whitney numbers of the second kind a(n,k), n >= 1, k >= 0, for the star poset. | [
"1",
"1",
"1",
"1",
"2",
"2",
"1",
"1",
"3",
"6",
"9",
"5",
"1",
"4",
"12",
"30",
"44",
"26",
"3",
"1",
"5",
"20",
"70",
"170",
"250",
"169",
"35",
"1",
"6",
"30",
"135",
"460",
"1110",
"1689",
"1254",
"340",
"15",
"1",
"7",
"42",
"231",
"1015",
"3430",
"8379",
"13083",
"10408",
"3409",
"315",
"1",
"8",
"56",
"364",
"1960",
"8540",
"28994",
"71512",
"114064",
"96116",
"36260"
] | [
"nonn",
"tabf",
"easy",
"nice"
] | 44 | 1 | 5 | [
"A007799",
"A192837"
] | null | Frederick J. Portier [fportier(AT)msmary.edu] | 2025-02-16T08:32:31 | oeisdata/seq/A007/A007799.seq | 514dae357303dd64d671b4534d758c95 |
A007800 | From a problem in AI planning: a(n) = 4+a(n-1)+a(n-2)+a(n-3)+a(n-4)-a(n-5)-a(n-6)-a(n-7), n>7. | [
"1",
"2",
"4",
"8",
"16",
"31",
"59",
"111",
"207",
"384",
"710",
"1310",
"2414",
"4445",
"8181",
"15053",
"27693",
"50942",
"93704",
"172356",
"317020",
"583099",
"1072495",
"1972635",
"3628251",
"6673404",
"12274314",
"22575994",
"41523738",
"76374073",
"140473833",
"258371673",
"475219609",
"874065146"
] | [
"nonn",
"easy"
] | 33 | 1 | 2 | [
"A007800",
"A062544"
] | null | Peter Jonsson [ petej(AT)ida.liu.se ] | 2024-05-22T02:11:20 | oeisdata/seq/A007/A007800.seq | 496a70af87c10f5d3c683ca86bc87fac |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.