Expansion of Product_{k>=0} ((1+x^(4*k+1))/(1-x^(4*k+1)))^3.

Terms

a(0) =1a(1) =6a(2) =18a(3) =38a(4) =66a(5) =108a(6) =182a(7) =306a(8) =486a(9) =728a(10) =1068a(11) =1578a(12) =2318a(13) =3312a(14) =4614a(15) =6388a(16) =8862a(17) =12192a(18) =16488a(19) =22038a(20) =29400a(21) =39156a(22) =51702a(23) =67554a(24) =87810a(25) =113982a(26) =147384a(27) =189200a(28) =241446a(29) =307356