OFFSET
0,2
FORMULA
a(n) ~ 2^(2*n + 1/2) * n^n / exp(n). - Vaclav Kotesovec, Nov 27 2017
MATHEMATICA
Table[Sum[Binomial[n+k, k]k!, {k, 0, n}], {n, 0, 100}] (* Emanuele Munarini, Sep 20 2016 *)
PROG
(Maxima) makelist(sum(binomial(n+k, k)*k!, k, 0, n), n, 0, 12); // Emanuele Munarini, Sep 20 2016 //
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Vladeta Jovovic, Aug 26 2005
STATUS
approved