A295439 a(n) = (9*n)!*(4*n)!/((8*n)!*(3*n)!*(2*n)!).

1, 18, 714, 32175, 1531530, 75167268, 3762157035, 190878381495, 9781950631050, 505159120481400, 26246321470970964, 1370400311694822954, 71844872838316074315, 3779480916094795749180, 199405648908172208299875, 10547211550872819183622800, 559103542410000371874708618

Offset: 0

Author

Gheorghe Coserea, Nov 23 2017

Keywords

• nonn

Crossrefs

Cf. A295431.

Programs

Mathematica

f[n_] := (9 n)! (4 n)!/((8 n)!*(3 n)! (2 n)!); Array[f, 17, 0] (* or *)CoefficientList[ Series[ HypergeometricPFQ[{1/9, 2/9, 4/9, 5/9, 7/9, 8/9}, {1/8, 3/8, 1/2, 5/8, 7/8}, 14348907/262144 x], {x, 0, 16}], x] (* Robert G. Wilson v, Nov 23 2017 *)

Formula

G.f.: hypergeom([1/9, 2/9, 4/9, 5/9, 7/9, 8/9], [1/8, 3/8, 1/2, 5/8, 7/8], 14348907/262144*x).

a(n) ~ 3^(15*n + 1/2) / (2^(18*n + 3/2) * sqrt(Pi*n)). - Vaclav Kotesovec, Jul 11 2025