This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A379659 #8 Dec 29 2024 08:49:10
%S A379659 1,3,35,766,25037,1096026,60318343,4004850718,311682426329,
%T A379659 27835056557650,2806352022690971,315328008662299062,
%U A379659 39076741980040016293,5294976627701723411866,778852468463039787264911,123599090729382829502733646,21049364262909179898132228017,3829309039543060842371185060770
%N A379659 Expansion of e.g.f. (1/x) * Series_Reversion( x * (exp(-x) - 2*x) ).
%F A379659 a(n) = n! * Sum_{k=0..n} 2^(n-k) * (2*n-k+1)^(k-1) * binomial(2*n-k+1,n-k)/k!.
%o A379659 (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!);
%Y A379659 Cf. A000272, A377890, A379660.
%K A379659 nonn
%O A379659 0,2
%A A379659 _Seiichi Manyama_, Dec 29 2024