A366178 G.f. A(x) satisfies A(x) = 1/(1 - x) + x*A(x)^3/(1 - x)^3.

1, 2, 10, 67, 502, 4045, 34279, 301232, 2720266, 25091431, 235394601, 2239139980, 21546299491, 209361514219, 2051379996574, 20245794958408, 201079938971546, 2008276118393320, 20157131084034349, 203215717750220949, 2056913539436637829

Offset: 0

Author

Seiichi Manyama, Oct 03 2023

Keywords

• nonn

Crossrefs

Partial sums give A366179.

Cf. A199475, A346626, A366177.

Programs

PARI

a(n) = sum(k=0, n, binomial(n+4*k, n-k)*binomial(3*k, k)/(2*k+1));

Formula

a(n) = Sum_{k=0..n} binomial(n+4*k,n-k) * binomial(3*k,k)/(2*k+1).