OFFSET
0,2
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..448
FORMULA
a(n) = Sum_{k=0..n} Sum_{m=0..n-k} abs(S1(n-k, m))*(m + 1)^k, where S1 indicates the signed Stirling numbers of first kind.
Conjecture: a(n) ~ n!. - Vaclav Kotesovec, May 26 2021
MATHEMATICA
Table[Sum[Sum[Abs[StirlingS1[n-k, m]](m+1)^k, {m, 0, n-k}], {k, 0, n}], {n, 0, 23}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Stefano Spezia, May 25 2021
STATUS
approved