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

Terms

a(0) =1a(1) =2a(2) =4a(3) =7a(4) =13a(5) =21a(6) =34a(7) =53a(8) =82a(9) =123a(10) =181a(11) =263a(12) =379a(13) =537a(14) =754a(15) =1047a(16) =1444a(17) =1972a(18) =2675a(19) =3601a(20) =4820a(21) =6408a(22) =8473a(23) =11141a(24) =14580a(25) =18985a(26) =24611a(27) =31765a(28) =40839a(29) =52294