Product_{n>=1} (1 + x^n)^a(n) = g.f. of A001970 (partitions of partitions).

Terms

a(0) =1a(1) =3a(2) =3a(3) =8a(4) =7a(5) =14a(6) =15a(7) =30a(8) =30a(9) =49a(10) =56a(11) =91a(12) =101a(13) =150a(14) =176a(15) =261a(16) =297a(17) =415a(18) =490a(19) =676a(20) =792a(21) =1058a(22) =1255a(23) =1666a(24) =1958a(25) =2537a(26) =3010a(27) =3868a(28) =4565a(29) =5780