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 A377490 #8 Oct 30 2024 08:04:28
%S A377490 1,2,24,560,19844,949632,57398980,4197775472,360541351092,
%T A377490 35581415127200,3968076446262116,493536896206210320,
%U A377490 67738259336620421140,10170114513821104697792,1658107523049271429191492,291735781263854493014688944,55097256018925972909190946932
%N A377490 E.g.f. satisfies A(x) = 1/(1 - A(x) * (exp(x*A(x)) - 1))^2.
%F A377490 E.g.f.: B(x)^2, where B(x) is the e.g.f. of A377495.
%F A377490 a(n) = 2 * Sum_{k=0..n} (2*n+3*k+1)!/(2*n+2*k+2)! * Stirling2(n,k).
%o A377490 (PARI) a(n) = 2*sum(k=0, n, (2*n+3*k+1)!/(2*n+2*k+2)!*stirling(n, k, 2));
%Y A377490 Cf. A367162, A377491.
%Y A377490 Cf. A377495.
%K A377490 nonn
%O A377490 0,2
%A A377490 _Seiichi Manyama_, Oct 29 2024