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 A302751 #4 Apr 12 2018 22:24:04
%S A302751 1,1,0,2,0,0,12,0,0,18,144,0,0,432,576,2880,0,4320,9408,23040,21600,
%T A302751 109440,172800,110880,662400,832320,2678400,4060800,10296000,9412992,
%U A302751 32922000,63676800,135734400,263556528,281030400,973036800,1906704000,4069224000,5184984960
%N A302751 Expansion of 1 + x*(1 + 2*x^2*(1 + 3*x^3*(1 + 4*x^4*(1 + ...)^4)^3)^2).
%e A302751 G.f. A(x) = 1 + x + 2*x^3 + 12*x^6 + 18*x^9 + 144*x^10 + 432*x^13 + 576*x^14 + 2880*x^15 + ...
%t A302751 nmax = 38; CoefficientList[Series[1 + x Fold[((#2 + 1) x^(#2 + 1) #1 + 1)^#2 &, 0, Reverse[Range[nmax]]], {x, 0, nmax}], x]
%Y A302751 Cf. A095793, A108643, A128318, A228866, A302688.
%K A302751 nonn
%O A302751 0,4
%A A302751 _Ilya Gutkovskiy_, Apr 12 2018