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 A363441 #14 Jun 03 2023 09:01:40
%S A363441 1,2,4,16,52,208,840,3520,15008,65344,288408,1288416,5813744,26460800,
%T A363441 121333200,559991712,2599385536,12127405952,56837861376,267473333120,
%U A363441 1263354463056,5987210061184,28461008374480,135672151034304,648406644570048
%N A363441 G.f. satisfies A(x) = exp( Sum_{k>=1} (-1)^(k+1) * A(x^k) * (2*x)^k/k ).
%H A363441 Seiichi Manyama, <a href="/A363441/b363441.txt">Table of n, a(n) for n = 0..1000</a>
%F A363441 A(x) = Sum_{k>=0} a(k) * x^k = Product_{k>=0} (1+2*x^(k+1))^a(k).
%F A363441 a(0) = 1; a(n) = (-1/n) * Sum_{k=1..n} ( Sum_{d|k} d * (-2)^(k/d) * a(d-1) ) * a(n-k).
%o A363441 (PARI) seq(n) = my(A=1); for(i=1, n, A=exp(sum(k=1, i, (-1)^(k+1)*subst(A, x, x^k)*(2*x)^k/k)+x*O(x^n))); Vec(A);
%Y A363441 Cf. A004111, A363442, A363443.
%Y A363441 Cf. A179469, A363425.
%K A363441 nonn
%O A363441 0,2
%A A363441 _Seiichi Manyama_, Jun 02 2023