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 A377746 #7 Nov 06 2024 04:38:13
%S A377746 1,3,31,637,19813,830671,43938067,2809979257,210946285417,
%T A377746 18189526062331,1771938448807591,192475338784416469,
%U A377746 23068103047077997069,3023954831626697490055,430420617664714578381019,66110112671342637934719121,10898800684623601950111879505,1919585083312849130822156455795
%N A377746 E.g.f. satisfies A(x) = exp(x) * (1 + x * A(x)^2)^2.
%F A377746 a(n) = n! * Sum_{k=0..n} (2*k+1)^(n-k-1) * binomial(4*k+2,k)/(n-k)!.
%o A377746 (PARI) a(n) = n!*sum(k=0, n, (2*k+1)^(n-k-1)*binomial(4*k+2, k)/(n-k)!);
%Y A377746 Cf. A377740.
%K A377746 nonn
%O A377746 0,2
%A A377746 _Seiichi Manyama_, Nov 06 2024