A379659 Expansion of e.g.f. (1/x) * Series_Reversion( x * (exp(-x) - 2*x) ).
1, 3, 35, 766, 25037, 1096026, 60318343, 4004850718, 311682426329, 27835056557650, 2806352022690971, 315328008662299062, 39076741980040016293, 5294976627701723411866, 778852468463039787264911, 123599090729382829502733646, 21049364262909179898132228017, 3829309039543060842371185060770
Offset: 0
Keywords
Programs
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PARI
a(n) = n!*sum(k=0, n, 2^(n-k)*(2*n-k+1)^(k-1)*binomial(2*n-k+1, n-k)/k!);
Formula
a(n) = n! * Sum_{k=0..n} 2^(n-k) * (2*n-k+1)^(k-1) * binomial(2*n-k+1,n-k)/k!.