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

Terms

a(0) =1a(1) =1a(2) =3a(3) =5a(4) =12a(5) =21a(6) =40a(7) =71a(8) =130a(9) =221a(10) =387a(11) =648a(12) =1095a(13) =1800a(14) =2964a(15) =4792a(16) =7730a(17) =12301a(18) =19510a(19) =30619a(20) =47859a(21) =74179a(22) =114469a(23) =175427a(24) =267684a(25) =406039a(26) =613325a(27) =921671a(28) =1379500a(29) =2055313