A366359 G.f. satisfies A(x) = 1/(1 - x) + x/A(x)^4.

1, 2, -7, 69, -715, 8351, -103735, 1346247, -18035023, 247520970, -3462344959, 49181268701, -707502644111, 10286493363184, -150913708053635, 2231345941617611, -33215679733509159, 497392118745778015, -7487512016559918595, 113242852989349372915

Offset: 0

Author

Seiichi Manyama, Oct 08 2023

Keywords

• sign

Crossrefs

Cf. A007317, A199475, A349289, A349290, A349291, A349292, A349293, A366356, A366357, A366358.

Cf. A364408, A366328, A366366.

Programs

PARI

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

Formula

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