A379287 G.f. A(x) satisfies A(x) = 1/((1 - x*A(x)^2) * (1 - x*A(x)^6)).

1, 2, 19, 268, 4477, 82110, 1597963, 32402460, 677152153, 14481799261, 315417278757, 6972246638416, 156017257712825, 3527275634678216, 80447862652931941, 1848737311902300600, 42766087499793329349, 995043161703028219128, 23271045049097437148389

Offset: 0

Author

Seiichi Manyama, Dec 19 2024

Keywords

• nonn

Crossrefs

Cf. A118969, A199475, A379209, A379284, A379285, A379286.

Programs

PARI

a(n) = sum(k=0, n, binomial(2*n+5*k+1, k)*binomial(3*n+3*k, n-k)/(2*n+5*k+1));

Formula

a(n) = Sum_{k=0..n} binomial(2*n+5*k+1,k) * binomial(3*n+3*k,n-k)/(2*n+5*k+1).