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

Terms

a(0) =1a(1) =3a(2) =6a(3) =10a(4) =16a(5) =33a(6) =44a(7) =74a(8) =126a(9) =204a(10) =289a(11) =503a(12) =696a(13) =1151a(14) =1749a(15) =2599a(16) =3742a(17) =5928a(18) =8245a(19) =12658a(20) =18351a(21) =26715a(22) =37828a(23) =55296a(24) =78346a(25) =111882a(26) =159664a(27) =226782a(28) =315416a(29) =446670