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%I #11 Dec 26 2017 21:36:05
%S 1,-1,0,-1,0,0,0,1,0,1,0,1,-1,1,-1,0,-1,0,-1,0,-1,0,0,0,0,0,1,0,1,0,1,
%T 0,1,0,1,-1,1,-1,1,-1,0,-1,0,-1,0,-1,0,-1,0,-1,0,0,0,0,0,0,0,1,0,1,0,
%U 1,0,1,0,1,0,1,0,1,-1,1,-1,1,-1,1,-1,0,-1,0,-1,0,-1,0,-1,0,-1,0
%N The coefficients of the product (1-x^2)(1-x^3)(1-x^4)... / (1+x).
%t iend = 100;
%t s = Series[1/(1 + x) Product[(1 - x^i), {i, 2, iend}], {x, 0, iend}];
%t Print[s]; Print[CoefficientList[s, x]]
%o (PARI) first(n) = Vec(prod(i=2, n-1, 1 - x^i)/(1 + x) + O(x^n)) \\ _Iain Fox_, Dec 24 2017
%K sign
%O 1
%A _David S. Newman_, Dec 24 2017