Expansion of Product_{k>=1} ((1 - x^k)/(1 + x^k))^(sigma(k)).

Terms

a(0) =1a(1) =-2a(2) =-4a(3) =2a(4) =10a(5) =22a(6) =-4a(7) =-26a(8) =-68a(9) =-104a(10) =-12a(11) =110a(12) =378a(13) =486a(14) =448a(15) =-66a(16) =-1130a(17) =-2242a(18) =-3044a(19) =-2474a(20) =-322a(21) =5106a(22) =11064a(23) =16954a(24) =17896a(25) =10440a(26) =-8032a(27) =-40132a(28) =-74578a(29) =-105754