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

Terms

a(0) =2a(1) =6a(2) =10a(3) =20a(4) =26a(5) =54a(6) =66a(7) =120a(8) =164a(9) =262a(10) =346a(11) =572a(12) =730a(13) =1110a(14) =1506a(15) =2182a(16) =2866a(17) =4156a(18) =5402a(19) =7612a(20) =9978a(21) =13638a(22) =17730a(23) =24200a(24) =31092a(25) =41558a(26) =53572a(27) =70692a(28) =90250a(29) =118406