A368937 Expansion of (1/x) * Series_Reversion( x * (1-x) * (1-x+x^5) ).

1, 2, 7, 30, 143, 727, 3861, 21165, 118845, 680064, 3951291, 23247874, 138229486, 829292780, 5013767772, 30516496017, 186837457296, 1149894814718, 7110026033305, 44146396259805, 275139524189497, 1720647439298395, 10793938343564655, 67905034046934225

Offset

0,2

Links

Table of n, a(n) for n=0..23.

Formula

a(n) = (1/(n+1)) * Sum_{k=0..floor(n/5)} (-1)^k * binomial(n+k,k) * binomial(3*n-4*k+1,n-5*k).

Prog

(PARI) a(n) = sum(k=0, n\5, (-1)^k*binomial(n+k, k)*binomial(3*n-4*k+1, n-5*k))/(n+1);
(PARI) my(N=30, x='x+O('x^N)); Vec(serreverse(x*(1-x)*(1-x+x^5))/x)

Crossrefs

Cf. A129442, A368935, A368936.

Cf. A366046, A368933.

Sequence in context: A368936 A260771 A260773 * A174796 A046648 A006013

Adjacent sequences: A368934 A368935 A368936 * A368938 A368939 A368940

Keyword

nonn

Author

Seiichi Manyama, Jan 10 2024

Status

approved