A366090 Expansion of (1/x) * Series_Reversion( x*(1-x)^4/(1-x-x^4) ).

1, 3, 15, 91, 611, 4370, 32637, 251550, 1985895, 15976676, 130508070, 1079562159, 9024791689, 76124252326, 647089873598, 5537663661590, 47670889706375, 412524981860848, 3586502483999720, 31311765471265548, 274398528604427286

Offset: 0

Author

Seiichi Manyama, Sep 28 2023

Keywords

• nonn

Crossrefs

Cf. A366086, A366087, A366088, A366089.

Cf. A366056.

Programs

PARI

a(n) = sum(k=0, n\4, (-1)^k*binomial(n+1, k)*binomial(4*n-3*k+2, n-4*k))/(n+1);

Formula

a(n) = (1/(n+1)) * Sum_{k=0..floor(n/4)} (-1)^k * binomial(n+1,k) * binomial(4*n-3*k+2,n-4*k).