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 A373708 #11 Jun 14 2024 10:04:05
%S A373708 1,1,1,1,1,241,1441,5041,13441,393121,10946881,99902881,559025281,
%T A373708 2335441681,182348406241,4382526067921,48882114328321,355837396998721,
%U A373708 5157802930734721,312898934463543361,7129755898022511361,89524038506304371761,773103613914955683361
%N A373708 Expansion of e.g.f. exp(x * (1 + x^4)^2).
%F A373708 a(n) = n! * Sum_{k=0..floor(2*n/9)} binomial(2*n-8*k,k)/(n-4*k)!.
%F A373708 a(n) == 1 (mod 240).
%F A373708 a(n) = a(n-1) + 10*(n-1)*(n-2)*(n-3)*(n-4)*a(n-5) + 9*(n-1)*(n-2)*(n-3)*(n-4)*(n-5)*(n-6)*(n-7)*(n-8)*a(n-9).
%o A373708 (PARI) a(n) = n!*sum(k=0, 2*n\9, binomial(2*n-8*k, k)/(n-4*k)!);
%Y A373708 Cf. A361278, A373578, A373707.
%Y A373708 Cf. A190877, A373524, A373525, A373526.
%Y A373708 Cf. A373706.
%K A373708 nonn
%O A373708 0,6
%A A373708 _Seiichi Manyama_, Jun 14 2024