OFFSET
0,4
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
KEYWORD
sign
AUTHOR
Seiichi Manyama, Sep 14 2017
STATUS
approved