A379253 G.f. A(x) satisfies A(x) = 1 + x * A(x)^2 * (1 + A(x)^5).

1, 2, 18, 250, 4114, 74274, 1422370, 28375578, 583343970, 12271614850, 262896435954, 5715805729274, 125797580340978, 2797216275743010, 62745424152317314, 1418139209556260250, 32263795396317233090, 738290052194219833346, 16981168956515987563730

Offset: 0

Author

Seiichi Manyama, Dec 19 2024

Keywords

• nonn

Crossrefs

Cf. A361638.

Programs

PARI

a(n) = sum(k=0, n, binomial(n, k)*binomial(2*n+5*k+1, n)/(2*n+5*k+1));

Formula

a(n) = Sum_{k=0..n} binomial(n,k) * binomial(2*n+5*k+1,n)/(2*n+5*k+1).