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 A381207 #12 Feb 17 2025 08:18:15
%S A381207 1,3,12,69,504,4335,43200,490161,6220032,87242427,1340305920,
%T A381207 22375475133,403237638144,7801208775399,161245892161536,
%U A381207 3545854432602345,82653484859228160,2035605515838402291,52814589875313573888,1439814136866851346357,41145786213980645621760
%N A381207 Expansion of e.g.f. 1/(1 - x*cosh(x))^3.
%C A381207 As stated in the comment of A185951, A185951(n,0) = 0^n.
%F A381207 a(n) = 1/2 * Sum_{k=0..n} (k+2)! * A185951(n,k).
%o A381207 (PARI) a185951(n, k) = binomial(n, k)/2^k*sum(j=0, k, (2*j-k)^(n-k)*binomial(k, j));
%o A381207 a(n) = sum(k=0, n, (k+2)!*a185951(n, k))/2;
%Y A381207 Cf. A377530, A381209, A381210, A381211.
%Y A381207 Cf. A205571, A381206.
%Y A381207 Cf. A185951.
%K A381207 nonn
%O A381207 0,2
%A A381207 _Seiichi Manyama_, Feb 17 2025