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

Terms

a(0) =1a(1) =4a(2) =6a(3) =4a(4) =5a(5) =16a(6) =24a(7) =20a(8) =26a(9) =48a(10) =56a(11) =60a(12) =98a(13) =132a(14) =130a(15) =168a(16) =253a(17) =288a(18) =324a(19) =448a(20) =539a(21) =588a(22) =780a(23) =1000a(24) =1086a(25) =1304a(26) =1690a(27) =1916a(28) =2205a(29) =2812