A192550 a(n) = sum(stirling2(n+1,k+1)*k!^2,k=0..n).

1, 2, 8, 68, 1052, 25772, 915308, 44417228, 2822059052, 227292363212, 22626053864108, 2727566236006988, 391549961731396652, 65997870405560143052, 12906384138105870075308, 2898250311530883985046348, 740679847516042935202775852

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

Sequence in context: A156448 A262479 A372315 * A157752 A055547 A113087

Adjacent sequences: A192547 A192548 A192549 * A192551 A192552 A192553

Keyword

nonn

Author

Emanuele Munarini, Jul 04 2011

Status

approved