A295481 a(n) = (24*n)!*(4*n)!*(3*n)!/((12*n)!*(9*n)!*(8*n)!*(2*n)!).

1, 6374082, 180669266788650, 5882199787281395215344, 202857467914154836183288657770, 7221430962039777689508936047385667332, 262302851034768406033478290202841394160147760, 9661245477414039526585354113472313766826824134193600

Offset

0,2

Links

Table of n, a(n) for n=0..7.

Formula

G.f.: hypergeom([1/24, 5/24, 7/24, 11/24, 13/24, 17/24, 19/24, 23/24], [1/9, 2/9, 4/9, 1/2, 5/9, 7/9, 8/9], 1073741824/27*x).

a(n) = binomial(24*n,12*n)*binomial(12*n,3*n)*binomial(3*n,n)/(binomial(8*n,4*n)*binomial(4*n,n)). - Chai Wah Wu, Feb 17 2026

a(n) ~ 2^(30*n-1) / (3^(3*n+1/2) * sqrt(Pi*n)). - Amiram Eldar, Feb 21 2026

Mathematica

a[n_] := (24*n)!*(4*n)!*(3*n)!/((12*n)!*(9*n)!*(8*n)!*(2*n)!); Array[a, 8, 0] (* Amiram Eldar, Feb 21 2026 *)

Prog

(Python)
from math import comb
def A295481(n): return comb(24*n, 12*n)*comb(12*n, 3*n)*comb(3*n, n)//(comb(8*n, 4*n)*comb(4*n, n)) # Chai Wah Wu, Feb 17 2026

Crossrefs

Cf. A295431.

Sequence in context: A141594 A307019 A234758 * A297327 A268843 A254174

Adjacent sequences: A295478 A295479 A295480 * A295482 A295483 A295484

Keyword

nonn,easy

Author

Gheorghe Coserea, Nov 28 2017

Status

approved