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 A377742 #12 Nov 06 2024 04:37:33
%S A377742 1,3,23,331,7133,205901,7470475,326932299,16768124217,986753701657,
%T A377742 65548017270791,4852285640543639,396133183892522389,
%U A377742 35359325061987638661,3426053898460864501251,358128187005971803014211,40172982580368589391407217,4813677071886578522596221233
%N A377742 E.g.f. satisfies A(x) = exp(x) / (1 - x * A(x))^2.
%F A377742 a(n) = n! * Sum_{k=0..n} (k+1)^(n-k-1) * binomial(3*k+1,k)/(n-k)!.
%o A377742 (PARI) a(n) = n!*sum(k=0, n, (k+1)^(n-k-1)*binomial(3*k+1, k)/(n-k)!);
%Y A377742 Cf. A194471, A377743, A377744.
%Y A377742 Cf. A001339, A377745.
%Y A377742 Cf. A377503.
%K A377742 nonn
%O A377742 0,2
%A A377742 _Seiichi Manyama_, Nov 05 2024