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 A373682 #8 Jun 13 2024 08:16:06
%S A373682 1,1,3,25,109,1401,11191,147673,1887705,26419249,454408651,7265533881,
%T A373682 148341346693,2804459457385,63733061703039,1419987630142201,
%U A373682 35144931608633521,902380834051682913,24277141650582775315,699721521711883149529,20520810981571082937501
%N A373682 Expansion of e.g.f. exp(x / (1 - x^2)^3) / (1 - x^2).
%F A373682 a(n) = n! * Sum_{k=0..floor(n/2)} binomial(3*n-5*k,k)/(n-2*k)!.
%F A373682 a(n) == 1 (mod 2).
%o A373682 (PARI) a(n) = n!*sum(k=0, n\2, binomial(3*n-5*k, k)/(n-2*k)!);
%Y A373682 Cf. A373681, A373683.
%Y A373682 Cf. A373668.
%K A373682 nonn
%O A373682 0,3
%A A373682 _Seiichi Manyama_, Jun 13 2024