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 A380754 #7 Feb 01 2025 08:42:16
%S A380754 1,3,49,1585,78093,5201771,437861149,44607800385,5338028587705,
%T A380754 734060947570867,114078994869344841,19773620424489710417,
%U A380754 3782330144139700656325,791450463143064447635355,179843077195936890250320373,44102411207136266014669068961,11609166496582801689148704120561
%N A380754 E.g.f. A(x) satisfies A(x) = exp(x * A(x)^2 / (1 - x * A(x)^2)) / (1 - x * A(x)^2)^2.
%F A380754 a(n) = n! * Sum_{k=0..n} (2*n+1)^(k-1) * binomial(5*n+1,n-k)/k!.
%o A380754 (PARI) a(n) = n!*sum(k=0, n, (2*n+1)^(k-1)*binomial(5*n+1, n-k)/k!);
%Y A380754 Cf. A380726.
%K A380754 nonn
%O A380754 0,2
%A A380754 _Seiichi Manyama_, Feb 01 2025