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 A377577 #8 Nov 02 2024 09:12:46
%S A377577 1,2,22,426,12344,480010,23500812,1389576230,96382531408,
%T A377577 7675512189714,690344499939860,69220070789605582,7656687699685355256,
%U A377577 926243380308839330426,121653259759077599227612,17240419344948437264399670,2622300119032920100004726432,426102385668766701871015106338
%N A377577 E.g.f. satisfies A(x) = (1 + x * exp(x) * A(x)^2)^2.
%F A377577 E.g.f.: B(x)^2, where B(x) is the e.g.f. of A364987.
%F A377577 a(n) = n! * Sum_{k=0..n} k^(n-k) * binomial(4*k+2,k)/( (2*k+1)*(n-k)! ).
%o A377577 (PARI) a(n) = n!*sum(k=0, n, k^(n-k)*binomial(4*k+2, k)/((2*k+1)*(n-k)!));
%Y A377577 Cf. A364987, A377576.
%K A377577 nonn
%O A377577 0,2
%A A377577 _Seiichi Manyama_, Nov 02 2024