A192556 a(n) = sum(abs(stirling1(n+1,k+1))*(-1)^(n-k)*k!^2,k=0..n).

1, 0, 3, 17, 330, 8074, 295792, 14593424, 939884432, 76503823776, 7681082731344, 932507036530992, 134658378428217696, 22811930868689642016, 4480422956516411159616, 1009922628068732158507584, 258952863907653970063080960

Offset

0,3

Links

Table of n, a(n) for n=0..16.

Formula

a(n) ~ exp(-1/2) * n!^2. - Vaclav Kotesovec, Jul 05 2021

Mathematica

Table[Sum[Abs[StirlingS1[n+1, k+1]](-1)^(n-k)k!^2, {k, 0, n}], {n, 0, 100}]

Prog

(Maxima) makelist(sum(abs(stirling1(n+1, k+1))*(-1)^(n-k)*k!^2, k, 0, n), n, 0, 24);

Crossrefs

Sequence in context: A290806 A009592 A051294 * A144033 A349643 A098138

Adjacent sequences: A192553 A192554 A192555 * A192557 A192558 A192559

Keyword

nonn

Author

Emanuele Munarini, Jul 04 2011

Status

approved