A366086 Expansion of (1/x) * Series_Reversion( x/(1-x-x^4) ).

1, -1, 1, -1, 0, 4, -14, 34, -65, 89, -29, -331, 1464, -4148, 9010, -14366, 9761, 38895, -215015, 674423, -1594973, 2829973, -2732465, -4812567, 36116257, -124617681, 316617081, -611942761, 735416371, 488457845, -6451021289, 24658985649, -66990721867, 139346533259

Offset: 0

Author

Seiichi Manyama, Sep 28 2023

Keywords

• sign

Crossrefs

Cf. A366087, A366088, A366089, A366090.

Cf. A366051, A366057.

Programs

PARI

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

Formula

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