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 A266943 #11 Dec 13 2023 08:36:38
%S A266943 1,4,16,52,160,452,1232,3204,8112,19956,48112,113732,264816,607876,
%T A266943 1379264,3096372,6888784,15201156,33306752,72510916,156972960,
%U A266943 338089844,724883552,1547816708,3292816416,6981664708,14758159472,31110217524,65415167744,137230388228
%N A266943 Expansion of Product_{k>=1} 1 / (1 - 2*x^k)^2.
%H A266943 Vaclav Kotesovec, <a href="/A266943/b266943.txt">Table of n, a(n) for n = 0..1000</a>
%F A266943 a(n) ~ c * n * 2^n, where c = 1/A048651^2 = 11.9906141505474711257730652493... .
%t A266943 nmax = 40; CoefficientList[Series[Product[1/(1-2*x^k)^2, {k, 1, nmax}], {x, 0, nmax}], x]
%Y A266943 Cf. A048651, A070933, A266944, A266945.
%K A266943 nonn
%O A266943 0,2
%A A266943 _Vaclav Kotesovec_, Jan 06 2016