Expansion of Sum_{k>0} x^(2*k)/(1+x^k)^4.

Terms

a(0) =0a(1) =1a(2) =-4a(3) =11a(4) =-20a(5) =32a(6) =-56a(7) =95a(8) =-124a(9) =146a(10) =-220a(11) =328a(12) =-364a(13) =400a(14) =-584a(15) =775a(16) =-816a(17) =881a(18) =-1140a(19) =1486a(20) =-1600a(21) =1552a(22) =-2024a(23) =2712a(24) =-2620a(25) =2562a(26) =-3400a(27) =4064a(28) =-4060a(29) =4112