A366182 G.f. A(x) satisfies A(x) = 1/(1 - x)^3 + x*A(x)^3/(1 - x).

1, 4, 19, 128, 1037, 9221, 86847, 851073, 8586951, 88598014, 930473246, 9913648325, 106891041270, 1164153791878, 12788021717902, 141518588447588, 1576271179332762, 17657110535606919, 198792746866201879, 2248222906227731856, 25529220583699163958

Offset: 0

Author

Seiichi Manyama, Oct 03 2023

Keywords

• nonn

Crossrefs

Partial sums of A366180.

Cf. A364623, A366183, A366184.

Programs

PARI

a(n) = sum(k=0, n, binomial(n+6*k+2, n-k)*binomial(3*k, k)/(2*k+1));

Formula

a(n) = Sum_{k=0..n} binomial(n+6*k+2,n-k) * binomial(3*k,k)/(2*k+1).