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

Terms

a(0) =1a(1) =1a(2) =3a(3) =7a(4) =14a(5) =27a(6) =56a(7) =101a(8) =190a(9) =347a(10) =617a(11) =1082a(12) =1895a(13) =3230a(14) =5490a(15) =9226a(16) =15332a(17) =25259a(18) =41356a(19) =67021a(20) =107989a(21) =172789a(22) =274613a(23) =433815a(24) =681650a(25) =1064661a(26) =1654739a(27) =2559029a(28) =3938438a(29) =6033967