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 A377551 #8 Nov 01 2024 09:30:05
%S A377551 1,4,28,348,6424,156900,4788024,175678468,7538078944,370557062532,
%T A377551 20540717542120,1267858489975044,86252943572785488,
%U A377551 6412719306748404676,517341051818833834648,45012757582472804739780,4201834386001491870902464,418891045572216881436564228
%N A377551 E.g.f. satisfies A(x) = 1/(1 - x * exp(x*A(x)))^4.
%F A377551 E.g.f.: B(x)^4, where B(x) is the e.g.f. of A377550.
%F A377551 a(n) = 4 * n! * Sum_{k=0..n} k^(n-k) * binomial(4*n-3*k+4,k)/( (4*n-3*k+4)*(n-k)! ).
%o A377551 (PARI) a(n) = 4*n!*sum(k=0, n, k^(n-k)*binomial(4*n-3*k+4, k)/((4*n-3*k+4)*(n-k)!));
%Y A377551 Cf. A161633, A377541, A377545.
%Y A377551 Cf. A377550, A377552.
%K A377551 nonn
%O A377551 0,2
%A A377551 _Seiichi Manyama_, Oct 31 2024