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 A303442 #12 Apr 25 2018 07:16:43
%S A303442 1,2,4,18,34,166,544,2222,5396,29622,101276,411206,1170986,5435466,
%T A303442 20007472,90854146,253956882,1160301990,4412414972,18080729238,
%U A303442 56012061494,275783908498,1010620487696,4103148863306,12730394683264,58227896627114,223877604671508
%N A303442 Expansion of Product_{k>=1} ((1 + 4^k*x^k)/(1 - 4^k*x^k))^(1/4^k).
%H A303442 Seiichi Manyama, <a href="/A303442/b303442.txt">Table of n, a(n) for n = 0..1000</a>
%t A303442 nmax = 30; CoefficientList[Series[Exp[Sum[((-1)^j - 1) / (j*(1 - 1/(4^(j-1)*x^j))), {j, 1, nmax}]], {x, 0, nmax}], x] (* _Vaclav Kotesovec_, Apr 25 2018 *)
%o A303442 (PARI) N=66; x='x+O('x^N); Vec(prod(k=1, N, ((1+4^k*x^k)/(1-4^k*x^k))^(1/4^k)))
%Y A303442 Cf. A303361, A303438, A303443.
%K A303442 nonn
%O A303442 0,2
%A A303442 _Seiichi Manyama_, Apr 24 2018