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

Terms

a(0) =1a(1) =2a(2) =4a(3) =6a(4) =10a(5) =15a(6) =22a(7) =31a(8) =44a(9) =60a(10) =82a(11) =109a(12) =145a(13) =189a(14) =246a(15) =316a(16) =405a(17) =513a(18) =648a(19) =811a(20) =1013a(21) =1256a(22) =1553a(23) =1908a(24) =2339a(25) =2852a(26) =3469a(27) =4200a(28) =5074a(29) =6105