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 A307724 #8 Apr 24 2019 19:44:57
%S A307724 0,1,1,3,12,64,402,2999,25100,236278,2444779,27725926,340761474,
%T A307724 4522224643,64378645709,979609661544,15862570817855,272466359964053,
%U A307724 4948142926019039,94748748685737418,1907956061833749740,40310880538563569017,891655630401500129652,20608302703021633063682
%N A307724 G.f. A(x) satisfies: A(x) = x*exp(Sum_{n>=1} Sum_{k>=1} n^k*a(n)^k*x^(n*k)/k).
%F A307724 G.f.: A(x) = Sum_{n>=1} a(n)*x^n = x * Product_{n>=1} 1/(1 - n*a(n)*x^n).
%F A307724 Recurrence: a(n+1) = (1/n) * Sum_{k=1..n} ( Sum_{d|k} d*(d*a(d))^(k/d) ) * a(n-k+1).
%e A307724 G.f.: A(x) = x + x^2 + 3*x^3 + 12*x^4 + 64*x^5 + 402*x^6 + 2999*x^7 + 25100*x^8 + 236278*x^9 + ...
%t A307724 a[n_] := a[n] = SeriesCoefficient[x Exp[Sum[Sum[j^k a[j]^k x^(j k)/k, {k, 1, n - 1}], {j, 1, n - 1}]], {x, 0, n}]; a[1] = 1; Table[a[n], {n, 0, 23}]
%t A307724 a[n_] := a[n] = SeriesCoefficient[x Product[1/(1 - k a[k] x^k), {k, 1, n - 1}], {x, 0, n}]; a[1] = 1; Table[a[n], {n, 0, 23}]
%Y A307724 Cf. A093637, A307725.
%K A307724 nonn
%O A307724 0,4
%A A307724 _Ilya Gutkovskiy_, Apr 24 2019