Product_{n>=1} (1 + a(n)*x^n) = 1 + Sum_{n>=1} phi(n)*x^n, where phi = A000010.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =-2a(6) =4a(7) =-3a(8) =4a(9) =-6a(10) =14a(11) =-18a(12) =30a(13) =-32a(14) =48a(15) =-73a(16) =128a(17) =-182a(18) =286a(19) =-394a(20) =578a(21) =-804a(22) =1386a(23) =-1936a(24) =3172a(25) =-4298a(26) =7102a(27) =-10202a(28) =16414a(29) =-23798