sequence_id string | sequence_name string | sequence_first_terms list | sequence_next_term string | is_easy int64 |
|---|---|---|---|---|
A000001 | Number of groups of order n. | [
"0",
"1",
"1",
"1",
"2",
"1",
"2",
"1",
"5",
"2",
"2",
"1",
"5",
"1",
"2",
"1",
"14",
"1",
"5"
] | 1 | 0 |
A000002 | Kolakoski sequence: a(n) is length of n-th run; a(1) = 1; sequence consists just of 1's and 2's. | [
"1",
"2",
"2",
"1",
"1",
"2",
"1",
"2",
"2",
"1",
"2",
"2",
"1",
"1",
"2",
"1",
"1",
"2",
"2"
] | 1 | 1 |
A000003 | Number of classes of primitive positive definite binary quadratic forms of discriminant D = -4n; or equivalently the class number of the quadratic order of discriminant D = -4n. | [
"1",
"1",
"1",
"1",
"2",
"2",
"1",
"2",
"2",
"2",
"3",
"2",
"2",
"4",
"2",
"2",
"4",
"2",
"3"
] | 4 | 1 |
A000004 | The zero sequence. | [
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0"
] | 0 | 1 |
A000005 | d(n) (also called tau(n) or sigma_0(n)), the number of divisors of n. | [
"1",
"2",
"2",
"3",
"2",
"4",
"2",
"4",
"3",
"4",
"2",
"6",
"2",
"4",
"4",
"5",
"2",
"6",
"2"
] | 6 | 1 |
A000006 | Integer part of square root of n-th prime. | [
"1",
"1",
"2",
"2",
"3",
"3",
"4",
"4",
"4",
"5",
"5",
"6",
"6",
"6",
"6",
"7",
"7",
"7",
"8"
] | 8 | 1 |
A000007 | The characteristic function of {0}: a(n) = 0^n. | [
"1",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0"
] | 0 | 1 |
A000008 | Number of ways of making change for n cents using coins of 1, 2, 5, 10 cents. | [
"1",
"1",
"2",
"2",
"3",
"4",
"5",
"6",
"7",
"8",
"11",
"12",
"15",
"16",
"19",
"22",
"25",
"28",
"31"
] | 34 | 1 |
A000009 | Expansion of Product_{m >= 1} (1 + x^m); number of partitions of n into distinct parts; number of partitions of n into odd parts. | [
"1",
"1",
"1",
"2",
"2",
"3",
"4",
"5",
"6",
"8",
"10",
"12",
"15",
"18",
"22",
"27",
"32",
"38",
"46"
] | 54 | 1 |
A000010 | Euler totient function phi(n): count numbers <= n and prime to n. | [
"1",
"1",
"2",
"2",
"4",
"2",
"6",
"4",
"6",
"4",
"10",
"4",
"12",
"6",
"8",
"8",
"16",
"6",
"18"
] | 8 | 1 |
A000011 | Number of n-bead necklaces (turning over is allowed) where complements are equivalent. | [
"1",
"1",
"2",
"2",
"4",
"4",
"8",
"9",
"18",
"23",
"44",
"63",
"122",
"190",
"362",
"612",
"1162",
"2056",
"3914"
] | 7155 | 1 |
A000012 | The simplest sequence of positive numbers: the all 1's sequence. | [
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1"
] | 1 | 1 |
A000013 | Definition (1): Number of n-bead binary necklaces with beads of 2 colors where the colors may be swapped but turning over is not allowed. | [
"1",
"1",
"2",
"2",
"4",
"4",
"8",
"10",
"20",
"30",
"56",
"94",
"180",
"316",
"596",
"1096",
"2068",
"3856",
"7316"
] | 13798 | 1 |
A000014 | Number of series-reduced trees with n nodes. | [
"0",
"1",
"1",
"0",
"1",
"1",
"2",
"2",
"4",
"5",
"10",
"14",
"26",
"42",
"78",
"132",
"249",
"445",
"842"
] | 1561 | 1 |
A000015 | Smallest prime power >= n. | [
"1",
"2",
"3",
"4",
"5",
"7",
"7",
"8",
"9",
"11",
"11",
"13",
"13",
"16",
"16",
"16",
"17",
"19",
"19"
] | 23 | 1 |
A000016 | a(n) is the number of distinct (infinite) output sequences from binary n-stage shift register which feeds back the complement of the last stage. | [
"1",
"1",
"1",
"2",
"2",
"4",
"6",
"10",
"16",
"30",
"52",
"94",
"172",
"316",
"586",
"1096",
"2048",
"3856",
"7286"
] | 13798 | 1 |
A000017 | Erroneous version of A032522. | [
"1",
"0",
"0",
"2",
"2",
"4",
"8",
"4",
"16",
"12",
"48",
"80",
"136",
"420",
"1240",
"2872",
"7652",
"18104"
] | 50184 | 0 |
A000018 | Number of positive integers <= 2^n of form x^2 + 16*y^2. | [
"1",
"1",
"2",
"2",
"4",
"8",
"13",
"25",
"44",
"83",
"152",
"286",
"538",
"1020",
"1942",
"3725",
"7145",
"13781",
"26627"
] | 51572 | 0 |
A000019 | Number of primitive permutation groups of degree n. | [
"1",
"1",
"2",
"2",
"5",
"4",
"7",
"7",
"11",
"9",
"8",
"6",
"9",
"4",
"6",
"22",
"10",
"4",
"8"
] | 4 | 0 |
A000020 | Number of primitive polynomials of degree n over GF(2) (version 2). | [
"2",
"1",
"2",
"2",
"6",
"6",
"18",
"16",
"48",
"60",
"176",
"144",
"630",
"756",
"1800",
"2048",
"7710",
"7776",
"27594"
] | 24000 | 0 |
A000021 | Number of positive integers <= 2^n of form x^2 + 12 y^2. | [
"1",
"1",
"2",
"2",
"6",
"9",
"17",
"30",
"54",
"98",
"183",
"341",
"645",
"1220",
"2327",
"4451",
"8555",
"16489",
"31859"
] | 61717 | 0 |
A000022 | Number of centered hydrocarbons with n atoms. | [
"0",
"1",
"0",
"1",
"1",
"2",
"2",
"6",
"9",
"20",
"37",
"86",
"181",
"422",
"943",
"2223",
"5225",
"12613",
"30513"
] | 74883 | 1 |
A000023 | Expansion of e.g.f. exp(-2*x)/(1-x). | [
"1",
"-1",
"2",
"-2",
"8",
"8",
"112",
"656",
"5504",
"49024",
"491264",
"5401856",
"64826368",
"842734592",
"11798300672",
"176974477312",
"2831591702528",
"48137058811904",
"866467058876416"
] | 16462874118127616 | 1 |
A000024 | Number of positive integers <= 2^n of form x^2 + 10 y^2. | [
"1",
"1",
"2",
"2",
"7",
"10",
"20",
"36",
"65",
"118",
"221",
"409",
"776",
"1463",
"2788",
"5328",
"10222",
"19714",
"38054"
] | 73685 | 0 |
A000025 | Coefficients of the 3rd-order mock theta function f(q). | [
"1",
"1",
"-2",
"3",
"-3",
"3",
"-5",
"7",
"-6",
"6",
"-10",
"12",
"-11",
"13",
"-17",
"20",
"-21",
"21",
"-27"
] | 34 | 1 |
A000026 | Mosaic numbers or multiplicative projection of n: if n = Product (p_j^k_j) then a(n) = Product (p_j * k_j). | [
"1",
"2",
"3",
"4",
"5",
"6",
"7",
"6",
"6",
"10",
"11",
"12",
"13",
"14",
"15",
"8",
"17",
"12",
"19"
] | 20 | 1 |
A000027 | The positive integers. Also called the natural numbers, the whole numbers or the counting numbers, but these terms are ambiguous. | [
"1",
"2",
"3",
"4",
"5",
"6",
"7",
"8",
"9",
"10",
"11",
"12",
"13",
"14",
"15",
"16",
"17",
"18",
"19"
] | 20 | 1 |
A000028 | Let k = p_1^e_1 p_2^e_2 p_3^e_3 ... be the prime factorization of n. Sequence gives k such that the sum of the numbers of 1's in the binary expansions of e_1, e_2, e_3, ... is odd. | [
"2",
"3",
"4",
"5",
"7",
"9",
"11",
"13",
"16",
"17",
"19",
"23",
"24",
"25",
"29",
"30",
"31",
"37",
"40"
] | 41 | 1 |
A000029 | Number of necklaces with n beads of 2 colors, allowing turning over (these are also called bracelets). | [
"1",
"2",
"3",
"4",
"6",
"8",
"13",
"18",
"30",
"46",
"78",
"126",
"224",
"380",
"687",
"1224",
"2250",
"4112",
"7685"
] | 14310 | 1 |
A000030 | Initial digit of n. | [
"0",
"1",
"2",
"3",
"4",
"5",
"6",
"7",
"8",
"9",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1",
"1"
] | 1 | 1 |
A000031 | Number of n-bead necklaces with 2 colors when turning over is not allowed; also number of output sequences from a simple n-stage cycling shift register; also number of binary irreducible polynomials whose degree divides n. | [
"1",
"2",
"3",
"4",
"6",
"8",
"14",
"20",
"36",
"60",
"108",
"188",
"352",
"632",
"1182",
"2192",
"4116",
"7712",
"14602"
] | 27596 | 1 |
A000032 | Lucas numbers beginning at 2: L(n) = L(n-1) + L(n-2), L(0) = 2, L(1) = 1. | [
"2",
"1",
"3",
"4",
"7",
"11",
"18",
"29",
"47",
"76",
"123",
"199",
"322",
"521",
"843",
"1364",
"2207",
"3571",
"5778"
] | 9349 | 1 |
A000033 | Coefficients of ménage hit polynomials. | [
"0",
"2",
"3",
"4",
"40",
"210",
"1477",
"11672",
"104256",
"1036050",
"11338855",
"135494844",
"1755206648",
"24498813794",
"366526605705",
"5851140525680",
"99271367764480",
"1783734385752162",
"33837677493828171"
] | 675799125332580020 | 1 |
A000034 | Period 2: repeat [1, 2]; a(n) = 1 + (n mod 2). | [
"1",
"2",
"1",
"2",
"1",
"2",
"1",
"2",
"1",
"2",
"1",
"2",
"1",
"2",
"1",
"2",
"1",
"2",
"1"
] | 2 | 1 |
A000035 | Period 2: repeat [0, 1]; a(n) = n mod 2; parity of n. | [
"0",
"1",
"0",
"1",
"0",
"1",
"0",
"1",
"0",
"1",
"0",
"1",
"0",
"1",
"0",
"1",
"0",
"1",
"0"
] | 1 | 1 |
A000036 | Let A(n) = #{(i,j): i^2 + j^2 <= n}, V(n) = Pi*n, P(n) = A(n) - V(n); A000099 gives values of n where |P(n)| sets a new record; sequence gives closest integer to P(A000099(n)). | [
"2",
"3",
"5",
"6",
"6",
"-6",
"7",
"8",
"10",
"13",
"13",
"13",
"14",
"-17",
"17",
"17",
"18",
"-19",
"20"
] | -22 | 0 |
A000037 | Numbers that are not squares (or, the nonsquares). | [
"2",
"3",
"5",
"6",
"7",
"8",
"10",
"11",
"12",
"13",
"14",
"15",
"17",
"18",
"19",
"20",
"21",
"22",
"23"
] | 24 | 1 |
A000038 | Twice A000007. | [
"2",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0",
"0"
] | 0 | 1 |
A000039 | Coefficient of q^(2n) in the series expansion of Ramanujan's mock theta function f(q). | [
"1",
"-2",
"-3",
"-5",
"-6",
"-10",
"-11",
"-17",
"-21",
"-27",
"-33",
"-46",
"-53",
"-68",
"-82",
"-104",
"-123",
"-154",
"-179"
] | -221 | 0 |
A000040 | The prime numbers. | [
"2",
"3",
"5",
"7",
"11",
"13",
"17",
"19",
"23",
"29",
"31",
"37",
"41",
"43",
"47",
"53",
"59",
"61",
"67"
] | 71 | 1 |
A000041 | a(n) is the number of partitions of n (the partition numbers). | [
"1",
"1",
"2",
"3",
"5",
"7",
"11",
"15",
"22",
"30",
"42",
"56",
"77",
"101",
"135",
"176",
"231",
"297",
"385"
] | 490 | 1 |
A000042 | Unary representation of natural numbers. | [
"1",
"11",
"111",
"1111",
"11111",
"111111",
"1111111",
"11111111",
"111111111",
"1111111111",
"11111111111",
"111111111111",
"1111111111111",
"11111111111111",
"111111111111111",
"1111111111111111",
"11111111111111111",
"111111111111111111",
"1111111111111111111"
] | 11111111111111111111 | 1 |
A000043 | Mersenne exponents: primes p such that 2^p - 1 is prime. Then 2^p - 1 is called a Mersenne prime. | [
"2",
"3",
"5",
"7",
"13",
"17",
"19",
"31",
"61",
"89",
"107",
"127",
"521",
"607",
"1279",
"2203",
"2281",
"3217",
"4253"
] | 4423 | 0 |
A000044 | Dying rabbits: a(0) = 1; for 1 <= n <= 12, a(n) = Fibonacci(n); for n >= 13, a(n) = a(n-1) + a(n-2) - a(n-13). | [
"1",
"1",
"1",
"2",
"3",
"5",
"8",
"13",
"21",
"34",
"55",
"89",
"144",
"232",
"375",
"606",
"979",
"1582",
"2556"
] | 4130 | 1 |
A000045 | Fibonacci numbers: F(n) = F(n-1) + F(n-2) with F(0) = 0 and F(1) = 1. | [
"0",
"1",
"1",
"2",
"3",
"5",
"8",
"13",
"21",
"34",
"55",
"89",
"144",
"233",
"377",
"610",
"987",
"1597",
"2584"
] | 4181 | 1 |
A000046 | Number of primitive n-bead necklaces (turning over is allowed) where complements are equivalent. | [
"1",
"1",
"1",
"1",
"2",
"3",
"5",
"8",
"14",
"21",
"39",
"62",
"112",
"189",
"352",
"607",
"1144",
"2055",
"3885"
] | 7154 | 1 |
A000047 | Number of integers <= 2^n of form x^2 - 2y^2. | [
"1",
"2",
"3",
"5",
"8",
"15",
"26",
"48",
"87",
"161",
"299",
"563",
"1066",
"2030",
"3885",
"7464",
"14384",
"27779",
"53782"
] | 104359 | 0 |
A000048 | Number of n-bead necklaces with beads of 2 colors and primitive period n, when turning over is not allowed but the two colors can be interchanged. | [
"1",
"1",
"1",
"1",
"2",
"3",
"5",
"9",
"16",
"28",
"51",
"93",
"170",
"315",
"585",
"1091",
"2048",
"3855",
"7280"
] | 13797 | 1 |
A000049 | Number of positive integers <= 2^n of the form 3*x^2 + 4*y^2. | [
"0",
"0",
"2",
"3",
"5",
"9",
"16",
"29",
"53",
"98",
"181",
"341",
"640",
"1218",
"2321",
"4449",
"8546",
"16482",
"31845"
] | 61707 | 0 |
A000050 | Number of positive integers <= 2^n of form x^2 + y^2. | [
"1",
"2",
"3",
"5",
"9",
"16",
"29",
"54",
"97",
"180",
"337",
"633",
"1197",
"2280",
"4357",
"8363",
"16096",
"31064",
"60108"
] | 116555 | 0 |
A000051 | a(n) = 2^n + 1. | [
"2",
"3",
"5",
"9",
"17",
"33",
"65",
"129",
"257",
"513",
"1025",
"2049",
"4097",
"8193",
"16385",
"32769",
"65537",
"131073",
"262145"
] | 524289 | 1 |
A000052 | 1-digit numbers arranged in alphabetical order, then the 2-digit numbers arranged in alphabetical order, then the 3-digit numbers, etc. | [
"8",
"5",
"4",
"9",
"1",
"7",
"6",
"3",
"2",
"0",
"18",
"80",
"88",
"85",
"84",
"89",
"81",
"87",
"86"
] | 83 | 0 |
A000053 | Local stops on New York City 1 Train (Broadway-7 Avenue Local) subway. | [
"14",
"18",
"23",
"28",
"34",
"42",
"50",
"59",
"66",
"72",
"79",
"86",
"96",
"103",
"110",
"116",
"125",
"137",
"145"
] | 157 | 0 |
A000054 | Local stops on New York City A line subway. | [
"4",
"14",
"23",
"34",
"42",
"50",
"59",
"72",
"81",
"86",
"96",
"103",
"110",
"116",
"125",
"135",
"145",
"155",
"163"
] | 168 | 0 |
A000055 | Number of trees with n unlabeled nodes. | [
"1",
"1",
"1",
"1",
"2",
"3",
"6",
"11",
"23",
"47",
"106",
"235",
"551",
"1301",
"3159",
"7741",
"19320",
"48629",
"123867"
] | 317955 | 1 |
A000056 | Order of the group SL(2,Z_n). | [
"1",
"6",
"24",
"48",
"120",
"144",
"336",
"384",
"648",
"720",
"1320",
"1152",
"2184",
"2016",
"2880",
"3072",
"4896",
"3888",
"6840"
] | 5760 | 1 |
A000057 | Primes dividing all Fibonacci sequences. | [
"2",
"3",
"7",
"23",
"43",
"67",
"83",
"103",
"127",
"163",
"167",
"223",
"227",
"283",
"367",
"383",
"443",
"463",
"467"
] | 487 | 0 |
A000058 | Sylvester's sequence: a(n+1) = a(n)^2 - a(n) + 1, with a(0) = 2. | [
"2",
"3",
"7",
"43",
"1807",
"3263443",
"10650056950807",
"113423713055421844361000443"
] | 12864938683278671740537145998360961546653259485195807 | 0 |
A000059 | Numbers k such that (2k)^4 + 1 is prime. | [
"1",
"2",
"3",
"8",
"10",
"12",
"14",
"17",
"23",
"24",
"27",
"28",
"37",
"40",
"41",
"44",
"45",
"53",
"59"
] | 66 | 1 |
A000060 | Number of signed trees with n nodes. | [
"1",
"2",
"3",
"10",
"27",
"98",
"350",
"1402",
"5743",
"24742",
"108968",
"492638",
"2266502",
"10600510",
"50235931",
"240882152",
"1166732814",
"5702046382",
"28088787314"
] | 139355139206 | 0 |
A000061 | Generalized tangent numbers d(n,1). | [
"1",
"1",
"2",
"4",
"4",
"6",
"8",
"8",
"12",
"14",
"14",
"16",
"20",
"20",
"24",
"32",
"24",
"30",
"38"
] | 32 | 0 |
A000062 | A Beatty sequence: a(n) = floor(n/(e-2)). | [
"1",
"2",
"4",
"5",
"6",
"8",
"9",
"11",
"12",
"13",
"15",
"16",
"18",
"19",
"20",
"22",
"23",
"25",
"26"
] | 27 | 0 |
A000063 | Symmetrical dissections of an n-gon. | [
"1",
"1",
"2",
"4",
"5",
"14",
"14",
"39",
"42",
"132",
"132",
"424",
"429",
"1428",
"1430",
"4848",
"4862",
"16796",
"16796"
] | 58739 | 0 |
A000064 | Partial sums of (unordered) ways of making change for n cents using coins of 1, 2, 5, 10 cents. | [
"1",
"2",
"4",
"6",
"9",
"13",
"18",
"24",
"31",
"39",
"50",
"62",
"77",
"93",
"112",
"134",
"159",
"187",
"218"
] | 252 | 1 |
A000065 | -1 + number of partitions of n. | [
"0",
"0",
"1",
"2",
"4",
"6",
"10",
"14",
"21",
"29",
"41",
"55",
"76",
"100",
"134",
"175",
"230",
"296",
"384"
] | 489 | 1 |
A000066 | Smallest number of vertices in trivalent graph with girth (shortest cycle) = n. | [
"4",
"6",
"10",
"14",
"24",
"30",
"58",
"70",
"112"
] | 126 | 0 |
A000067 | Number of positive integers <= 2^n of form x^2 + 2 y^2. | [
"1",
"2",
"4",
"6",
"10",
"18",
"33",
"60",
"111",
"205",
"385",
"725",
"1374",
"2610",
"4993",
"9578",
"18426",
"35568",
"68806"
] | 133411 | 0 |
A000068 | Numbers k such that k^4 + 1 is prime. | [
"1",
"2",
"4",
"6",
"16",
"20",
"24",
"28",
"34",
"46",
"48",
"54",
"56",
"74",
"80",
"82",
"88",
"90",
"106"
] | 118 | 1 |
A000069 | Odious numbers: numbers with an odd number of 1's in their binary expansion. | [
"1",
"2",
"4",
"7",
"8",
"11",
"13",
"14",
"16",
"19",
"21",
"22",
"25",
"26",
"28",
"31",
"32",
"35",
"37"
] | 38 | 1 |
A000070 | a(n) = Sum_{k=0..n} p(k) where p(k) = number of partitions of k (A000041). | [
"1",
"2",
"4",
"7",
"12",
"19",
"30",
"45",
"67",
"97",
"139",
"195",
"272",
"373",
"508",
"684",
"915",
"1212",
"1597"
] | 2087 | 1 |
A000071 | a(n) = Fibonacci(n) - 1. | [
"0",
"0",
"1",
"2",
"4",
"7",
"12",
"20",
"33",
"54",
"88",
"143",
"232",
"376",
"609",
"986",
"1596",
"2583",
"4180"
] | 6764 | 1 |
A000072 | Number of positive integers <= 2^n of form x^2 + 4 y^2. | [
"1",
"1",
"2",
"4",
"7",
"12",
"22",
"41",
"72",
"137",
"254",
"476",
"901",
"1716",
"3274",
"6286",
"12090",
"23331",
"45140"
] | 87511 | 0 |
A000073 | Tribonacci numbers: a(n) = a(n-1) + a(n-2) + a(n-3) for n >= 3 with a(0) = a(1) = 0 and a(2) = 1. | [
"0",
"0",
"1",
"1",
"2",
"4",
"7",
"13",
"24",
"44",
"81",
"149",
"274",
"504",
"927",
"1705",
"3136",
"5768",
"10609"
] | 19513 | 1 |
A000074 | Number of odd integers <= 2^n of form x^2 + y^2. | [
"1",
"1",
"2",
"4",
"7",
"13",
"25",
"43",
"83",
"157",
"296",
"564",
"1083",
"2077",
"4006",
"7733",
"14968",
"29044",
"56447"
] | 109864 | 0 |
A000075 | Number of positive integers <= 2^n of form 2 x^2 + 3 y^2. | [
"0",
"1",
"2",
"4",
"7",
"14",
"23",
"42",
"76",
"139",
"258",
"482",
"907",
"1717",
"3269",
"6257",
"12020",
"23171",
"44762"
] | 86683 | 0 |
A000076 | Number of integers <= 2^n of form 4 x^2 + 4 x y + 5 y^2. | [
"0",
"0",
"1",
"2",
"4",
"7",
"14",
"24",
"43",
"82",
"149",
"284",
"534",
"1015",
"1937",
"3713",
"7136",
"13759",
"26597"
] | 51537 | 0 |
A000077 | Number of positive integers <= 2^n of form x^2 + 6 y^2. | [
"1",
"1",
"2",
"4",
"8",
"13",
"24",
"42",
"76",
"140",
"257",
"483",
"907",
"1717",
"3272",
"6261",
"12027",
"23172",
"44769"
] | 86708 | 0 |
A000078 | Tetranacci numbers: a(n) = a(n-1) + a(n-2) + a(n-3) + a(n-4) for n >= 4 with a(0) = a(1) = a(2) = 0 and a(3) = 1. | [
"0",
"0",
"0",
"1",
"1",
"2",
"4",
"8",
"15",
"29",
"56",
"108",
"208",
"401",
"773",
"1490",
"2872",
"5536",
"10671"
] | 20569 | 1 |
A000079 | Powers of 2: a(n) = 2^n. | [
"1",
"2",
"4",
"8",
"16",
"32",
"64",
"128",
"256",
"512",
"1024",
"2048",
"4096",
"8192",
"16384",
"32768",
"65536",
"131072",
"262144"
] | 524288 | 1 |
A000080 | Number of nonisomorphic minimal triangle graphs. | [
"1",
"1",
"2",
"4",
"9",
"19",
"48",
"117",
"307",
"821",
"2277",
"6437",
"18634",
"54775",
"163703",
"495529",
"1518706",
"4703848",
"14714754"
] | 46444979 | 0 |
A000081 | Number of unlabeled rooted trees with n nodes (or connected functions with a fixed point). | [
"0",
"1",
"1",
"2",
"4",
"9",
"20",
"48",
"115",
"286",
"719",
"1842",
"4766",
"12486",
"32973",
"87811",
"235381",
"634847",
"1721159"
] | 4688676 | 1 |
A000082 | a(n) = n^2*Product_{p|n} (1 + 1/p). | [
"1",
"6",
"12",
"24",
"30",
"72",
"56",
"96",
"108",
"180",
"132",
"288",
"182",
"336",
"360",
"384",
"306",
"648",
"380"
] | 720 | 1 |
A000083 | Number of mixed Husimi trees with n nodes; or polygonal cacti with bridges. | [
"1",
"1",
"1",
"2",
"4",
"9",
"23",
"63",
"188",
"596",
"1979",
"6804",
"24118",
"87379",
"322652",
"1209808",
"4596158",
"17657037",
"68497898"
] | 268006183 | 0 |
A000084 | Number of series-parallel networks with n unlabeled edges. Also called yoke-chains by Cayley and MacMahon. | [
"1",
"2",
"4",
"10",
"24",
"66",
"180",
"522",
"1532",
"4624",
"14136",
"43930",
"137908",
"437502",
"1399068",
"4507352",
"14611576",
"47633486",
"156047204"
] | 513477502 | 1 |
A000085 | Number of self-inverse permutations on n letters, also known as involutions; number of standard Young tableaux with n cells. | [
"1",
"1",
"2",
"4",
"10",
"26",
"76",
"232",
"764",
"2620",
"9496",
"35696",
"140152",
"568504",
"2390480",
"10349536",
"46206736",
"211799312",
"997313824"
] | 4809701440 | 1 |
A000086 | Number of solutions to x^2 - x + 1 == 0 (mod n). | [
"1",
"0",
"1",
"0",
"0",
"0",
"2",
"0",
"0",
"0",
"0",
"0",
"2",
"0",
"0",
"0",
"0",
"0",
"2"
] | 0 | 1 |
A000087 | Number of unrooted nonseparable planar maps with n edges and a distinguished face. | [
"2",
"1",
"2",
"4",
"10",
"37",
"138",
"628",
"2972",
"14903",
"76994",
"409594",
"2222628",
"12281570",
"68864086",
"391120036",
"2246122574",
"13025721601",
"76194378042"
] | 449155863868 | 0 |
A000088 | Number of simple graphs on n unlabeled nodes. | [
"1",
"1",
"2",
"4",
"11",
"34",
"156",
"1044",
"12346",
"274668",
"12005168",
"1018997864",
"165091172592",
"50502031367952",
"29054155657235488",
"31426485969804308768",
"64001015704527557894928",
"245935864153532932683719776",
"1787577725145611700547878190848"
] | 24637809253125004524383007491432768 | 0 |
A000089 | Number of solutions to x^2 + 1 == 0 (mod n). | [
"1",
"1",
"0",
"0",
"2",
"0",
"0",
"0",
"0",
"2",
"0",
"0",
"2",
"0",
"0",
"0",
"2",
"0",
"0"
] | 0 | 0 |
A000090 | Expansion of e.g.f. exp((-x^3)/3)/(1-x). | [
"1",
"1",
"2",
"4",
"16",
"80",
"520",
"3640",
"29120",
"259840",
"2598400",
"28582400",
"343235200",
"4462057600",
"62468806400",
"936987251200",
"14991796019200",
"254860532326400",
"4587501779660800"
] | 87162533813555200 | 1 |
A000091 | Multiplicative with a(2^e) = 2 for k >= 1; a(3) = 2, a(3^e) = 0 for k >= 2; a(p^e) = 0 if p > 3 and p == -1 (mod 3); a(p^e) = 2 if p > 3 and p == 1 (mod 3). | [
"1",
"2",
"2",
"2",
"0",
"4",
"2",
"2",
"0",
"0",
"0",
"4",
"2",
"4",
"0",
"2",
"0",
"0",
"2"
] | 0 | 1 |
A000092 | Let A(n) = #{(i,j,k): i^2 + j^2 + k^2 <= n}, V(n) = (4/3)Pi*n^(3/2), P(n) = A(n) - V(n); sequence gives values of n where |P(n)| sets a new record. | [
"1",
"2",
"5",
"6",
"14",
"21",
"29",
"30",
"54",
"90",
"134",
"155",
"174",
"230",
"234",
"251",
"270",
"342",
"374"
] | 461 | 0 |
A000093 | a(n) = floor(n^(3/2)). | [
"0",
"1",
"2",
"5",
"8",
"11",
"14",
"18",
"22",
"27",
"31",
"36",
"41",
"46",
"52",
"58",
"64",
"70",
"76"
] | 82 | 1 |
A000094 | Number of trees of diameter 4. | [
"0",
"0",
"0",
"0",
"1",
"2",
"5",
"8",
"14",
"21",
"32",
"45",
"65",
"88",
"121",
"161",
"215",
"280",
"367"
] | 471 | 0 |
A000095 | Number of fixed points of GAMMA_0 (n) of type i. | [
"1",
"2",
"0",
"0",
"2",
"0",
"0",
"0",
"0",
"4",
"0",
"0",
"2",
"0",
"0",
"0",
"2",
"0",
"0"
] | 0 | 1 |
A000096 | a(n) = n*(n+3)/2. | [
"0",
"2",
"5",
"9",
"14",
"20",
"27",
"35",
"44",
"54",
"65",
"77",
"90",
"104",
"119",
"135",
"152",
"170",
"189"
] | 209 | 1 |
A000097 | Number of partitions of n if there are two kinds of 1's and two kinds of 2's. | [
"1",
"2",
"5",
"9",
"17",
"28",
"47",
"73",
"114",
"170",
"253",
"365",
"525",
"738",
"1033",
"1422",
"1948",
"2634",
"3545"
] | 4721 | 1 |
A000098 | Number of partitions of n if there are two kinds of 1, two kinds of 2 and two kinds of 3. | [
"1",
"2",
"5",
"10",
"19",
"33",
"57",
"92",
"147",
"227",
"345",
"512",
"752",
"1083",
"1545",
"2174",
"3031",
"4179",
"5719"
] | 7752 | 1 |
A000099 | Let A(n) = #{(i,j): i^2 + j^2 <= n}, V(n) = Pi*n, P(n) = A(n) - V(n); sequence gives values of n where |P(n)| sets a new record. | [
"1",
"2",
"5",
"10",
"20",
"24",
"26",
"41",
"53",
"130",
"149",
"205",
"234",
"287",
"340",
"410",
"425",
"480",
"586"
] | 840 | 0 |
A000100 | a(n) is the number of compositions of n in which the maximal part is 3. | [
"0",
"0",
"0",
"1",
"2",
"5",
"11",
"23",
"47",
"94",
"185",
"360",
"694",
"1328",
"2526",
"4781",
"9012",
"16929",
"31709"
] | 59247 | 1 |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.