Inverse Moebius transform of A000048 (starting at term 0).

Terms

a(0) =1a(1) =2a(2) =2a(3) =3a(4) =3a(5) =6a(6) =6a(7) =12a(8) =18a(9) =32a(10) =52a(11) =100a(12) =171a(13) =322a(14) =589a(15) =1103a(16) =2049a(17) =3877a(18) =7281a(19) =13830a(20) =26221a(21) =49982a(22) =95326a(23) =182470a(24) =349523a(25) =671260a(26) =1290573a(27) =2485827a(28) =4793491a(29) =9257016