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

Terms

a(0) =1a(1) =2a(2) =2a(3) =4a(4) =8a(5) =10a(6) =14a(7) =24a(8) =34a(9) =44a(10) =62a(11) =86a(12) =116a(13) =156a(14) =206a(15) =274a(16) =362a(17) =462a(18) =598a(19) =782a(20) =994a(21) =1258a(22) =1606a(23) =2018a(24) =2528a(25) =3178a(26) =3952a(27) =4904a(28) =6094a(29) =7490