A365977 Expansion of e.g.f. 1 / ( 1 - Sum_{k>=0} x^(5*k+1) / (5*k+1) ).

1, 1, 2, 6, 24, 120, 840, 6720, 60480, 604800, 6652800, 83462400, 1138233600, 16746912000, 264176640000, 4444771968000, 80719172352000, 1556132497920000, 31722198842880000, 681437830993920000, 15378172899747840000, 366025806545817600000

Offset

0,3

Links

Table of n, a(n) for n=0..21.

Formula

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

Prog

(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(1/(1-sum(k=0, N\5, x^(5*k+1)/(5*k+1)))))

Crossrefs

Cf. A296676, A365975, A365976.

Cf. A365969.

Sequence in context: A352430 A292749 A351984 * A079854 A024923 A334395

Adjacent sequences: A365974 A365975 A365976 * A365978 A365979 A365980

Keyword

nonn

Author

_Seiichi Manyama_, Sep 23 2023

Status

approved