A292308 E.g.f.: 1/Product_{k>=1} (1 + x^k/k!).

1, -1, 1, -4, 21, -96, 520, -3795, 32053, -284368, 2763876, -30648465, 373339824, -4833294389, 67167087793, -1009753574739, 16215467043493, -275361718915824, 4947532173402532, -94054153646919213, 1882793796608183356, -39528099512321898363

Offset

0,4

Links

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

Formula

a(n) = (-1)^n * A076901(n).

a(n) ~ c * (-1)^n * n!, where c = Product_{k>=2} (1 + (-1)^k/k!) = 0.77351587386... - Vaclav Kotesovec, Sep 14 2017

Mathematica

nmax = 20; Table[SeriesCoefficient[Product[1/(1 + x^k/k!), {k, 1, n}], {x, 0, n}], {n, 0, nmax}] * Range[0, nmax]! (* Vaclav Kotesovec, Sep 14 2017 *)

Crossrefs

Cf. A005651, A007837, A076901.

Sequence in context: A220574 A231377 A017967 * A076901 A080043 A240456

Adjacent sequences: A292305 A292306 A292307 * A292309 A292310 A292311

Keyword

sign

Author

Seiichi Manyama, Sep 14 2017

Status

approved