Expansion of Product_{k>=1} ((1+x^(3*k-1))*(1+x^(3*k-2)))^k.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =4a(6) =4a(7) =7a(8) =9a(9) =11a(10) =16a(11) =23a(12) =31a(13) =40a(14) =53a(15) =71a(16) =91a(17) =121a(18) =161a(19) =206a(20) =264a(21) =343a(22) =441a(23) =563a(24) =725a(25) =922a(26) =1166a(27) =1476a(28) =1869a(29) =2357