A366216 G.f. A(x) satisfies A(x) = 1 + x*(1 + x)^4*A(x)^4.

1, 1, 8, 60, 520, 4886, 48384, 497460, 5259872, 56834345, 624819148, 6966612604, 78592083420, 895432704860, 10288759392156, 119089472755860, 1387274092156508, 16251727492295812, 191342076640423136, 2262894045516407118, 26869820052175649836

Offset

0,3

Links

Table of n, a(n) for n=0..20.

Formula

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

Prog

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

Crossrefs

Cf. A073155, A366200.

Sequence in context: A373757 A160228 A274746 * A317774 A099337 A356595

Adjacent sequences: A366213 A366214 A366215 * A366217 A366218 A366219

Keyword

nonn

Author

Seiichi Manyama, Oct 04 2023

Status

approved