Expansion of Product_{i>=1, j>=1, k>=1, l>=1} (1 - x^(i*j*k*l))/(1 + x^(i*j*k*l)).

Terms

a(0) =1a(1) =-2a(2) =-6a(3) =6a(4) =14a(5) =30a(6) =-14a(7) =-98a(8) =-86a(9) =-150a(10) =282a(11) =486a(12) =502a(13) =670a(14) =-1118a(15) =-1226a(16) =-4396a(17) =-3814a(18) =1326a(19) =3834a(20) =20354a(21) =16330a(22) =18334a(23) =-6606a(24) =-45658a(25) =-60762a(26) =-121770a(27) =-60122a(28) =-22750a(29) =160314