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 A285215 #27 Apr 16 2017 07:33:31 %S A285215 1,1,3,6,9,20,36,62,106,184,302,503,829,1325,2119,3367,5282,8227, %T A285215 12740,19550,29849,45300,68325,102495,152998,227249,336005,494597, %U A285215 724875,1058213,1538860,2229370,3218304,4630015,6638728,9488894,13520995,19208916,27211430 %N A285215 Expansion of Product_{k>=1} (1 - x^(4*k))^(4*k) / (1 - x^k)^k. %H A285215 Seiichi Manyama, <a href="/A285215/b285215.txt">Table of n, a(n) for n = 0..10000</a> %F A285215 G.f.: Product_{k>=0} 1 / ((1-x^(4*k+1))^(4*k+1) * (1-x^(4*k+2))^(4*k+2) * (1-x^(4*k+3))^(4*k+3)). %F A285215 a(n) ~ exp(-1/4 + 2^(-4/3) * 3^(4/3) * Zeta(3)^(1/3) * n^(2/3)) * A^3 * Zeta(3)^(1/12) / (2^(5/4) * 3^(5/12) * sqrt(Pi) * n^(7/12)), where A is the Glaisher-Kinkelin constant A074962. - _Vaclav Kotesovec_, Apr 16 2017 %t A285215 nmax = 50; CoefficientList[Series[Product[1 / ((1-x^(4*k+1))^(4*k+1) * (1-x^(4*k+2))^(4*k+2) * (1-x^(4*k+3))^(4*k+3)), {k,0,nmax}], {x,0,nmax}], x] (* _Vaclav Kotesovec_, Apr 15 2017 *) %t A285215 nmax = 50; CoefficientList[Series[Product[(1 - x^(4*k))^(4*k)/((1 - x^k)^k), {k,1,nmax}], {x,0,nmax}], x] (* _Vaclav Kotesovec_, Apr 15 2017 *) %o A285215 (PARI) x='x+O('x^100); Vec(prod(k=0, 100, 1 / ((1 - x^(4*k + 1))^(4*k + 1)*(1 - x^(4*k + 2))^(4*k + 2)*(1 - x^(4*k + 3))^(4*k + 3)))) \\ _Indranil Ghosh_, Apr 15 2017 %Y A285215 Product_{k>=1} (1 - x^(m*k))^(m*k)/(1 - x^k)^k: A262811 (m=2), A262923 (m=3), this sequence (m=4), A285246 (m=5). %Y A285215 Cf. A285262, A285284. %K A285215 nonn %O A285215 0,3 %A A285215 _Seiichi Manyama_, Apr 15 2017