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A111420
a(n) = Sum_{q=0..n} Stirling2(n+1,q)^2*q!.
3
0, 1, 19, 315, 6601, 178923, 6161065, 262268499, 13470911521, 818285112123, 57836073876505, 4693152951066099, 432360761046527041, 44794795435021490043, 5176959026638375267225, 662704551819559746282579, 93384393940399990403502241, 14406589076081640590750974203
OFFSET
0,3
MAPLE
a:= n-> add(Stirling2(n+1, q)^2*q!, q=0..n):
seq(a(n), n=0..19); # Alois P. Heinz, May 11 2020
MATHEMATICA
Table[Sum[StirlingS2[n+1, k]^2 * k!, {k, 0, n}], {n, 0, 20}] (* Vaclav Kotesovec, Jul 12 2018 *)
CROSSREFS
Sequence in context: A142430 A180845 A138943 * A166965 A372193 A137352
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Nov 14 2005
STATUS
approved