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 A377894 #10 Feb 16 2025 08:34:07
%S A377894 1,2,11,142,2725,71026,2339719,93311758,4371948137,235418287042,
%T A377894 14327098759171,972533690209390,72854996624174989,5970582808814848498,
%U A377894 531359818098465084863,51034785131352404960686,5261620527219949295345233,579593410301187097865649922
%N A377894 E.g.f. satisfies A(x) = (1 + x) * exp(x * A(x)^2).
%H A377894 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/LambertW-Function.html">Lambert W-Function</a>.
%F A377894 E.g.f.: (1+x) * exp( -LambertW(-2*x*(1+x)^2)/2 ).
%F A377894 E.g.f.: ( -LambertW(-2*x*(1+x)^2)/(2*x) )^(1/2).
%F A377894 a(n) = n! * Sum_{k=0..n} (2*k+1)^(k-1) * binomial(2*k+1,n-k)/k!.
%o A377894 (PARI) a(n) = n!*sum(k=0, n, (2*k+1)^(k-1)*binomial(2*k+1, n-k)/k!);
%Y A377894 Cf. A377826, A377895.
%K A377894 nonn
%O A377894 0,2
%A A377894 _Seiichi Manyama_, Nov 11 2024