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%I #8 May 11 2020 15:21:36
%S 0,1,19,315,6601,178923,6161065,262268499,13470911521,818285112123,
%T 57836073876505,4693152951066099,432360761046527041,
%U 44794795435021490043,5176959026638375267225,662704551819559746282579,93384393940399990403502241,14406589076081640590750974203
%N a(n) = Sum_{q=0..n} Stirling2(n+1,q)^2*q!.
%p a:= n-> add(Stirling2(n+1,q)^2*q!, q=0..n):
%p seq(a(n), n=0..19); # _Alois P. Heinz_, May 11 2020
%t Table[Sum[StirlingS2[n+1, k]^2 * k!, {k, 0, n}], {n, 0, 20}] (* _Vaclav Kotesovec_, Jul 12 2018 *)
%Y Cf. A023997, A014235.
%K nonn
%O 0,3
%A _N. J. A. Sloane_, Nov 14 2005
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