A357933 a(n) = Sum_{k=0..floor(n/5)} |Stirling1(n - 4*k,n - 5*k)|.

1, 1, 1, 1, 1, 1, 2, 4, 7, 11, 16, 24, 40, 72, 131, 231, 395, 675, 1187, 2161, 4006, 7414, 13609, 24951, 46210, 86930, 165528, 316682, 606047, 1161343, 2237329, 4345777, 8507103, 16738587, 33030166, 65352308, 129821251, 259254283, 520531422, 1049771054, 2124315222

Offset

0,7

Links

Table of n, a(n) for n=0..40.

Formula

G.f.: Sum_{k>=0} x^k * Product_{j=0..k-1} (1 + j * x^4).

Prog

(PARI) a(n) = sum(k=0, n\5, abs(stirling(n-4*k, n-5*k, 1)));
(PARI) my(N=50, x='x+O('x^N)); Vec(sum(k=0, N, x^k*prod(j=0, k-1, 1+j*x^4)))

Crossrefs

Cf. A124380, A357931, A357932.

Sequence in context: A099385 A331387 A357308 * A237821 A120118 A108895

Adjacent sequences: A357930 A357931 A357932 * A357934 A357935 A357936

Keyword

nonn

Author

Seiichi Manyama, Oct 21 2022

Status

approved