Expansion of Sum_{0<i<j<k<l} q^(i+j+k+l)/( (1-q^i)*(1-q^j)*(1-q^k)*(1-q^l) )^2.

Terms

a(0) =1a(1) =3a(2) =9a(3) =22a(4) =51a(5) =97a(6) =188a(7) =330a(8) =568a(9) =918a(10) =1452a(11) =2233a(12) =3344a(13) =4884a(14) =7004a(15) =9856a(16) =13653a(17) =18699a(18) =25080a(19) =33462a(20) =43918a(21) =57304a(22) =73668a(23) =94482a(24) =119262a(25) =150285a(26) =187231a(27) =232560a(28) =285660a(29) =350746