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 A264687 #7 May 06 2018 04:44:09
%S A264687 0,1,1,2,2,5,4,11,10,22,22,50,43,104,100,209,206,446,418,914,886,1838,
%T A264687 1825,3800,3664,7696,7591,15470,15370,31466,30910,63398,62866,127154,
%U A264687 126742,256559,254156,515168,513004,1032104,1029997,2073626,2063866,4156118
%N A264687 a(n) = 2^n - A006951(n).
%H A264687 Vaclav Kotesovec, <a href="/A264687/b264687.txt">Table of n, a(n) for n = 0..1000</a>
%F A264687 a(n) ~ (1+sqrt(2) + (-1)^n*(1-sqrt(2))) * 2^(n/2 - 1).
%t A264687 nmax = 60; 2^Range[0, nmax] - CoefficientList[Series[Product[(1 - x^k)/(1 - 2*x^k), {k, 1, nmax}], {x, 0, nmax}], x]
%Y A264687 Cf. A006951, A304082.
%K A264687 nonn
%O A264687 0,4
%A A264687 _Vaclav Kotesovec_, Nov 21 2015