A379252 G.f. A(x) satisfies A(x) = ( (1 + x*A(x))/(1 - x*A(x)^3) )^2.

1, 4, 40, 572, 9552, 174004, 3352440, 67171500, 1385457568, 29220437860, 627287390664, 13661411796508, 301096488681200, 6703186665881876, 150517000234338072, 3404956079399106700, 77526315562007606080, 1775260286963982001860, 40857405217738915499880, 944584396250976659451388

Offset: 0

Author

Seiichi Manyama, Dec 19 2024

Keywords

• nonn

Crossrefs

Cf. A006319, A032349, A379251.

Cf. A379253.

Programs

PARI

a(n) = sum(k=0, n, binomial(2*n+5*k+1, k)*binomial(2*n+4*k+2, n-k)/(n+2*k+1));

Formula

G.f.: B(x)^2 where B(x) is the g.f. of A379253.

a(n) = Sum_{k=0..n} binomial(2*n+5*k+1,k) * binomial(2*n+4*k+2,n-k)/(n+2*k+1).