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 A383204 #7 Apr 19 2025 10:04:10
%S A383204 0,0,1,9,70,550,4531,39515,365324,3575820,36971461,402741581,
%T A383204 4610187154,55316069874,694067320311,9087012399007,123889735839000,
%U A383204 1755654433460248,25816120675972105,393285627390135313,6198118449550830302,100916786871955767998,1695424878199285059003
%N A383204 Expansion of e.g.f. f(x)^2 * exp(f(x)) / 2, where f(x) = (exp(2*x) - 1)/2.
%F A383204 a(n) = Sum_{k=2..n} 2^(n-k) * binomial(k,2) * Stirling2(n,k).
%o A383204 (PARI) a(n) = sum(k=2, n, 2^(n-k)*binomial(k, 2)*stirling(n, k, 2));
%Y A383204 Column k=2 of A154602.
%K A383204 nonn
%O A383204 0,4
%A A383204 _Seiichi Manyama_, Apr 19 2025