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 A292520 #17 Jul 25 2022 08:34:54
%S A292520 1,-1,1,-1,0,0,0,0,1,-2,2,-2,1,0,0,0,0,-1,2,-2,2,-1,0,0,0,-1,2,-3,3,
%T A292520 -2,1,0,1,-2,3,-4,3,-2,1,0,1,-2,3,-4,3,-2,1,0,0,-2,4,-5,6,-4,2,-1,0,
%U A292520 -2,5,-7,8,-6,3,-1,0,-1,3,-6,7,-6,4,-1,1,-1,3,-6,7,-8,6,-3,2,-4,6,-9,11,-9,7,-4,1,-3,7
%N A292520 Expansion of Product_{k>=1} 1/(1 + x^(k^2)).
%C A292520 Convolution inverse of A033461.
%C A292520 The difference between the number of partitions of n into an even number of squares and the number of partitions of n into an odd number of squares.
%H A292520 Vaclav Kotesovec, <a href="/A292520/b292520.txt">Table of n, a(n) for n = 0..20000</a>
%H A292520 Martin Klazar, <a href="http://arxiv.org/abs/1808.08449">What is an answer? — remarks, results and problems on PIO formulas in combinatorial enumeration, part I</a>, arXiv:1808.08449 [math.CO], 2018.
%H A292520 <a href="/index/Par#part">Index entries for related partition-counting sequences</a>
%F A292520 G.f.: Product_{k>=1} 1/(1 + x^(k^2)).
%F A292520 a(n) ~ (-1)^n * exp(3 * Pi^(1/3) * Zeta(3/2)^(2/3) * n^(1/3) / 2^(7/3)) * Zeta(3/2)^(1/3) / (2^(5/3) * sqrt(3) * Pi^(1/3) * n^(5/6)). - _Vaclav Kotesovec_, Sep 19 2017
%F A292520 a(n) = Sum_{k=0..n} (-1)^k * A243148(n,k). - _Alois P. Heinz_, Jul 25 2022
%t A292520 nmax = 100; CoefficientList[Series[Product[1/(1 + x^(k^2)), {k, 1, Floor[Sqrt[nmax]] + 1}], {x, 0, nmax}], x] (* _Vaclav Kotesovec_, Sep 19 2017 *)
%Y A292520 Cf. A001156, A033461, A081362, A243148, A276516, A279225, A279226.
%K A292520 sign
%O A292520 0,10
%A A292520 _Ilya Gutkovskiy_, Sep 18 2017