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 A373707 #12 Jun 14 2024 10:08:21
%S A373707 1,1,1,1,49,241,721,6721,124321,913249,4243681,94818241,1640604241,
%T A373707 14642181841,131026944049,3669304504321,62536989802561,
%U A373707 627395160826561,10818406189690561,308036857749752449,5219006583104930161,65146235714284117681
%N A373707 Expansion of e.g.f. exp(x * (1 + x^3)^2).
%F A373707 a(n) = n! * Sum_{k=0..floor(2*n/7)} binomial(2*n-6*k,k)/(n-3*k)!.
%F A373707 a(n) == 1 (mod 48).
%F A373707 a(n) = a(n-1) + 8*(n-1)*(n-2)*(n-3)*a(n-4) + 7*(n-1)*(n-2)*(n-3)*(n-4)*(n-5)*(n-6)*a(n-7).
%o A373707 (PARI) a(n) = n!*sum(k=0, 2*n\7, binomial(2*n-6*k, k)/(n-3*k)!);
%Y A373707 Cf. A361278, A373578, A373708.
%Y A373707 Cf. A190875, A373522, A373523.
%Y A373707 Cf. A373680.
%K A373707 nonn
%O A373707 0,5
%A A373707 _Seiichi Manyama_, Jun 14 2024