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 A309703 #7 Aug 13 2019 13:18:44
%S A309703 1,1,3,5,13,22,48,88,184,342,684,1298,2556,4880,9506,18240,35366,
%T A309703 67992,131446,253044,488532,941014,1815334,3497924,6745360,12999632,
%U A309703 25063130,48306046,93123674,179492482,346003572,666925774,1285580868,2478002696,4776580902,9207090240
%N A309703 G.f. A(x) satisfies: A(x) = A(x^2) / (1 - x - x^2 - x^3 - x^4).
%F A309703 G.f.: Product_{k>=0} 1/(1 - x^(2^k) - x^(2^(k+1)) - x^(3*2^k) - x^(2^(k+2))).
%t A309703 nmax = 35; A[_] = 1; Do[A[x_] = A[x^2]/(1 - x - x^2 - x^3 - x^4) + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
%t A309703 nmax = 35; CoefficientList[Series[Product[1/(1 - x^(2^k) - x^(2^(k + 1)) - x^(3 2^k) - x^(2^(k + 2))), {k, 0, Floor[Log[2, nmax]] + 1}], {x, 0, nmax}], x]
%Y A309703 Cf. A000078, A018819, A173285, A309702.
%K A309703 nonn
%O A309703 0,3
%A A309703 _Ilya Gutkovskiy_, Aug 13 2019