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 A305207 #5 May 27 2018 19:47:06
%S A305207 1,1,3,13,95,921,11586,176324,3162447,65233120,1521743103,39609506223,
%T A305207 1138093049808,35779807446670,1221719353617885,45025117385882889,
%U A305207 1781345658408660655,75304205654268663567,3387556543611248410593,161575661076504392490150,8144909167115962980271095
%N A305207 a(n) = [x^n] exp(Sum_{k>=1} x^k/(k*(1 - n*x^k))).
%H A305207 N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>
%F A305207 a(n) = [x^n] Product_{k>=1} 1/(1 - x^k)^(n^(k-1)).
%t A305207 Table[SeriesCoefficient[Exp[Sum[x^k/(k (1 - n x^k)), {k, 1, n}]], {x, 0, n}], {n, 0, 20}]
%t A305207 Table[SeriesCoefficient[Product[1/(1 - x^k)^(n^(k - 1)), {k, 1, n}], {x, 0, n}], {n, 0, 20}]
%Y A305207 Cf. A034691, A104460, A252654, A305209.
%K A305207 nonn
%O A305207 0,3
%A A305207 _Ilya Gutkovskiy_, May 27 2018