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

Terms

a(0) =1a(1) =4a(2) =7a(3) =17a(4) =25a(5) =58a(6) =87a(7) =177a(8) =289a(9) =528a(10) =860a(11) =1550a(12) =2486a(13) =4257a(14) =6910a(15) =11474a(16) =18335a(17) =29941a(18) =47331a(19) =75819a(20) =118887a(21) =187338a(22) =290784a(23) =452904a(24) =696058a(25) =1071234a(26) =1632947a(27) =2487504a(28) =3759613a(29) =5676424