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 A377689 #10 Nov 04 2024 09:08:18
%S A377689 1,0,6,9,300,1995,48438,720111,17965944,422161011,12234150930,
%T A377689 380328463383,13151800946628,497667965729259,20320277028840558,
%U A377689 899482574279597535,42525760204244934768,2153233176660303831267,115738033009558749725610,6600044862098481204272487
%N A377689 E.g.f. satisfies A(x) = (1 + x * (exp(x*A(x)) - 1))^3.
%F A377689 E.g.f.: B(x)^3, where B(x) is the e.g.f. of A377690.
%F A377689 a(n) = 3 * n! * Sum_{k=0..floor(n/2)} (3*n-3*k+2)! * Stirling2(n-k,k)/( (n-k)! * (3*n-4*k+3)! ).
%o A377689 (PARI) a(n) = 3*n!*sum(k=0, n\2, (3*n-3*k+2)!*stirling(n-k, k, 2)/((n-k)!*(3*n-4*k+3)!));
%Y A377689 Cf. A371115, A377688.
%Y A377689 Cf. A377690.
%K A377689 nonn
%O A377689 0,3
%A A377689 _Seiichi Manyama_, Nov 04 2024