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 A285287 #12 Apr 16 2017 10:27:32
%S A285287 1,-1,1,-1,1,-6,6,-6,6,-15,30,-30,30,-43,88,-123,123,-140,250,-385,
%T A285287 455,-476,678,-1098,1413,-1564,1913,-2918,4048,-4707,5452,-7572,10747,
%U A285287 -13265,15195,-19534,27349,-35146,41042,-50011,67596,-88897,106519,-126635,164230
%N A285287 Expansion of Product_{k>=0} 1/(1 + x^(4*k+1))^(4*k+1).
%H A285287 Seiichi Manyama, <a href="/A285287/b285287.txt">Table of n, a(n) for n = 0..10000</a>
%F A285287 a(n) = (-1)^n * A285048(n).
%t A285287 nmax = 50; CoefficientList[Series[Product[1/(1 + x^(4*k-3))^(4*k-3), {k,1,nmax}], {x,0,nmax}], x] (* _Vaclav Kotesovec_, Apr 16 2017 *)
%Y A285287 Product_{k>=0} 1/(1 + x^(m*k+1))^(m*k+1): A284628 (m=2), A285286 (m=3), this sequence (m=4).
%Y A285287 Cf. A285048, A285288.
%K A285287 sign
%O A285287 0,6
%A A285287 _Seiichi Manyama_, Apr 16 2017