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 A339352 #4 Dec 01 2020 17:07:24
%S A339352 1,-1,1,-1,2,-2,1,-1,2,-3,2,-2,4,-5,4,-4,7,-8,7,-7,9,-10,8,-8,11,-14,
%T A339352 13,-13,16,-18,17,-16,19,-22,23,-23,26,-29,29,-30,34,-38,38,-39,44,
%U A339352 -48,47,-48,56,-64,65,-66,75,-82,80,-80,90,-99,98,-100,114
%N A339352 G.f.: Product_{k>=1} (1 + (-x)^(k^2) / (1 + x^k)).
%C A339352 The difference between the number of partitions of n into an even number of parts where every part k appears at least k times and the number of partitions of n into an odd number of parts where every part k appears at least k times.
%t A339352 nmax = 60; CoefficientList[Series[Product[1 + (-x)^(k^2)/(1 + x^k), {k, 1, nmax}], {x, 0, nmax}], x]
%Y A339352 Cf. A081362, A117144.
%K A339352 sign
%O A339352 0,5
%A A339352 _Ilya Gutkovskiy_, Dec 01 2020