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 A265821 #5 Dec 15 2015 18:59:00
%S A265821 1,1,1,1,5,5,5,12,28,28,38,66,130,143,232,344,616,738,1094,1561,2840,
%T A265821 3671,5117,7227,12833,16182,22428,32205,57058,71006,98684,141253,
%U A265821 241563,301889,421994,610113,1018507,1278706,1784671,2549610,4224964,5333003,7491698
%N A265821 Expansion of Product_{k>=1} 1/(1 - (3*k-2)*x^(3*k-2)).
%H A265821 Vaclav Kotesovec, <a href="/A265821/b265821.txt">Table of n, a(n) for n = 0..5000</a>
%F A265821 a(n) ~ c * 2^(n/2), where
%F A265821 c = 4.633065657780064798394952757560310709647495826095820632429... if mod(n,4) = 0
%F A265821 c = 4.169885941972377533366541853673119715620037601993736640548... if mod(n,4) = 1
%F A265821 c = 4.088913297791237602600754017373520586356446410096065167531... if mod(n,4) = 2
%F A265821 c = 4.069986547973463713613958049535085419215417774875202440925... if mod(n,4) = 3.
%t A265821 nmax = 40; CoefficientList[Series[Product[1/(1 - (3*k-2)*x^(3*k-2)), {k, 1, nmax}], {x, 0, nmax}], x]
%Y A265821 Cf. A067553, A265820.
%K A265821 nonn
%O A265821 0,5
%A A265821 _Vaclav Kotesovec_, Dec 15 2015