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

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =5a(5) =7a(6) =9a(7) =12a(8) =15a(9) =18a(10) =22a(11) =27a(12) =33a(13) =40a(14) =48a(15) =57a(16) =67a(17) =79a(18) =93a(19) =109a(20) =127a(21) =147a(22) =170a(23) =196a(24) =226a(25) =260a(26) =298a(27) =340a(28) =387a(29) =440