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

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =7a(5) =14a(6) =22a(7) =40a(8) =65a(9) =107a(10) =176a(11) =282a(12) =448a(13) =705a(14) =1101a(15) =1701a(16) =2611a(17) =3977a(18) =6021a(19) =9048a(20) =13527a(21) =20102a(22) =29720a(23) =43712a(24) =63997a(25) =93259a(26) =135317a(27) =195539a(28) =281440a(29) =403559