A379256 G.f. A(x) satisfies A(x) = 1 + x * A(x)^3 * (1 + A(x)^4).

1, 2, 20, 296, 5168, 98896, 2006592, 42403584, 923292672, 20570204672, 466681402112, 10744734700032, 250415336695808, 5896251565619200, 140051037257007104, 3351752341884928000, 80744484314316193792, 1956433860220223062016, 47647871136991576260608

Offset

0,2

Links

Table of n, a(n) for n=0..18.

Formula

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

Prog

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

Crossrefs

Cf. A379257.

Sequence in context: A349963 A246482 A124211 * A277308 A373314 A128481

Adjacent sequences: A379253 A379254 A379255 * A379257 A379258 A379259

Keyword

nonn

Author

Seiichi Manyama, Dec 19 2024

Status

approved