G.f.: x + x^2 / Product_{n>=1} (1 - a(n)*x^n).

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =6a(6) =10a(7) =20a(8) =36a(9) =73a(10) =138a(11) =281a(12) =549a(13) =1136a(14) =2263a(15) =4705a(16) =9553a(17) =20015a(18) =41096a(19) =86643a(20) =179638a(21) =380701a(22) =795892a(23) =1693003a(24) =3562217a(25) =7612680a(26) =16099538a(27) =34505797a(28) =73345831a(29) =157678081