A370701 Expansion of e.g.f. exp(-x^3)/(1-x).

1, 1, 2, 0, 0, 0, 360, 2520, 20160, 120960, 1209600, 13305600, 179625600, 2335132800, 32691859200, 479480601600, 7671689625600, 130418723635200, 2356429211136000, 44772155011584000, 895443100231680000, 18794168013164544000, 413471696289619968000

Offset

0,3

Links

Table of n, a(n) for n=0..22.

Formula

a(n) = n! * Sum_{k=0..floor(n/3)} (-1)^k/k!.

Prog

(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(exp(-x^3)/(1-x)))
(PARI) a(n) = n!*sum(k=0, n\3, (-1)^k/k!);

Crossrefs

Cf. A000166, A370700.

Cf. A370696.

Sequence in context: A193542 A193545 A336399 * A086260 A124505 A326855

Adjacent sequences: A370698 A370699 A370700 * A370702 A370703 A370704

Keyword

nonn,easy

Author

Seiichi Manyama, Feb 27 2024

Status

approved