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 A363423 #15 Jun 02 2023 10:19:17
%S A363423 1,1,4,40,1126,92440,22559276,16468584194,36033333480881,
%T A363423 236450784546518006,4654297351684653345788,
%U A363423 274836259327539399144691019,48686693681325683653963188907344,25874153864215746591981599665978198380
%N A363423 G.f. satisfies A(x) = exp( Sum_{k>=1} A(3*x^k) * x^k/k ).
%H A363423 Seiichi Manyama, <a href="/A363423/b363423.txt">Table of n, a(n) for n = 0..65</a>
%F A363423 A(x) = Sum_{k>=0} a(k) * x^k = 1/Product_{k>=0} (1-x^(k+1))^(3^k * a(k)).
%F A363423 a(0) = 1; a(n) = (1/n) * Sum_{k=1..n} ( Sum_{d|k} d * 3^(d-1) * a(d-1) ) * a(n-k).
%o A363423 (PARI) seq(n) = my(A=1); for(i=1, n, A=exp(sum(k=1, i, subst(A, x, 3*x^k)*x^k/k)+x*O(x^n))); Vec(A);
%Y A363423 Cf. A000081, A179470, A363424.
%Y A363423 Cf. A359018.
%K A363423 nonn
%O A363423 0,3
%A A363423 _Seiichi Manyama_, Jun 01 2023