OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..41
FORMULA
a(n) ~ sqrt(e)*(n!)^2. - Vaclav Kotesovec, Jan 02 2013
MATHEMATICA
Table[Sum[StirlingS2[n+1, k+1]k!^2, {k, 0, n}], {n, 0, 100}]
PROG
(Maxima) makelist(sum(stirling2(n+1, k+1)*k!^2, k, 0, n), n, 0, 12);
CROSSREFS
KEYWORD
nonn
AUTHOR
Emanuele Munarini, Jul 04 2011
STATUS
approved