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 A307779 #7 Apr 28 2019 20:09:52
%S A307779 1,1,1,2,2,3,4,5,5,7,8,9,11,12,13,17,17,18,22,23,25,31,32,33,38,41,42,
%T A307779 49,51,52,63,64,64,74,75,82,93,94,95,108,113,114,130,131,133,155,156,
%U A307779 157,174,179,187,206,208,209,231,242,247,271,272,273,307,308,309,345,345
%N A307779 a(1) = 1; a(n+1) = Sum_{d|n, n/d odd} a(d).
%F A307779 G.f.: x * (1 + Sum_{n>=1} a(n)*x^n/(1 - x^(2*n))).
%F A307779 L.g.f.: log(Product_{n>=1} ((1 + x^n)/(1 - x^n))^(a(n)/(2*n))) = Sum_{n>=1} a(n+1)*x^n/n.
%t A307779 a[n_] := a[n] = Sum[Boole[OddQ[(n - 1)/d]] a[d], {d, Divisors[n - 1]}]; a[1] = 1; Table[a[n], {n, 1, 65}]
%t A307779 a[n_] := a[n] = SeriesCoefficient[x (1 + Sum[a[k] x^k/(1 - x^(2 k)), {k, 1, n - 1}]), {x, 0, n}]; Table[a[n], {n, 1, 65}]
%Y A307779 Cf. A002033, A003238, A307776, A307777, A307778.
%K A307779 nonn
%O A307779 1,4
%A A307779 _Ilya Gutkovskiy_, Apr 28 2019