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 A360987 #23 Jul 06 2025 10:39:57
%S A360987 1,1,-3,-23,233,3521,-62171,-1416407,35880977,1095318721,-36224195059,
%T A360987 -1387587617239,56675849155705,2612993427672577,-127090039302776395,
%U A360987 -6852033608852338199,386750643197222855969,23875394847093826450049
%N A360987 E.g.f. A(x) satisfies A(x) = exp(x * A(-x)^2).
%C A360987 Sum_{k=0..n} (2*n - 2*k + 1)^(k-1) * (2*k)^(n-k) * binomial(n,k) = (2*n+1)^(n-1) = A052750(n). - _Vaclav Kotesovec_, Jul 03 2025
%H A360987 Seiichi Manyama, <a href="/A360987/b360987.txt">Table of n, a(n) for n = 0..367</a>
%F A360987 a(n) = Sum_{k=0..n} (2*n - 2*k + 1)^(k-1) * (-2*k)^(n-k) * binomial(n,k).
%F A360987 a(0) = 1; a(n) = (-1)^(n-1) * (n-1)! * Sum_{i, j, k>=0 and i+j+k=n-1} (-1)^i * (n-i) * a(i) * a(j) * a(k)/(i! * j! * k!). - _Seiichi Manyama_, Jul 06 2025
%o A360987 (PARI) a(n) = sum(k=0, n, (2*n-2*k+1)^(k-1)*(-2*k)^(n-k)*binomial(n, k));
%Y A360987 Cf. A052750, A141369, A196198, A360988, A360989, A360990.
%Y A360987 Cf. A168600.
%K A360987 sign
%O A360987 0,3
%A A360987 _Seiichi Manyama_, Feb 27 2023