A366405 G.f. A(x) satisfies A(x) = (1 + x / A(x)^(5/2)) / (1 - x).

1, 2, -3, 22, -138, 1012, -7839, 63506, -531024, 4549276, -39723484, 352237844, -3163252976, 28711196184, -262964888021, 2427319896584, -22557930343459, 210889624536396, -1981972609174109, 18714482015314016, -177453862702083994, 1689045253793239952

Offset: 0

Author

Seiichi Manyama, Oct 09 2023

Keywords

• sign

Crossrefs

Cf. A366400, A366401, A366402, A366403, A366404, A366406, A366407.

Programs

PARI

a(n) = (-1)^(n-1)*sum(k=0, n, binomial(7*k/2-1, k)*binomial(5*k/2-1, n-k)/(7*k/2-1));

Formula

a(n) = (-1)^(n-1) * Sum_{k=0..n} binomial(7*k/2-1,k) * binomial(5*k/2-1,n-k) / (7*k/2-1).