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 A363481 #14 Jun 05 2023 08:53:44
%S A363481 1,2,11,108,1969,67542,4473663,582167944,150236569819,77226088637142,
%T A363481 79235069050108841,162432444097491547308,665648716390456030366881,
%U A363481 5454326724964994060395500598,89374602386639273949112262243227
%N A363481 G.f. satisfies A(x) = exp( 2 * Sum_{k>=1} A(2*x^k) * x^k/k ).
%H A363481 Seiichi Manyama, <a href="/A363481/b363481.txt">Table of n, a(n) for n = 0..80</a>
%F A363481 A(x) = B(x)^2 where B(x) is the g.f. of A363480.
%F A363481 A(x) = Sum_{k>=0} a(k) * x^k = 1/Product_{k>=0} (1-x^(k+1))^(2^(k+1) * a(k)).
%F A363481 a(0) = 1; a(n) = (1/n) * Sum_{k=1..n} ( Sum_{d|k} d * 2^d * a(d-1) ) * a(n-k).
%o A363481 (PARI) seq(n) = my(A=1); for(i=1, n, A=exp(2*sum(k=1, i, subst(A, x, 2*x^k)*x^k/k)+x*O(x^n))); Vec(A);
%Y A363481 Cf. A000151, A179469, A179470, A363480.
%K A363481 nonn
%O A363481 0,2
%A A363481 _Seiichi Manyama_, Jun 04 2023