Number of 9-almost primes 9ap such that 2^n < 9ap <= 2^(n+1).

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =0a(8) =1a(9) =1a(10) =5a(11) =8a(12) =22a(13) =47a(14) =102a(15) =232a(16) =482a(17) =1062a(18) =2217a(19) =4738a(20) =10051a(21) =21083a(22) =44315a(23) =92608a(24) =193824a(25) =402936a(26) =838879a(27) =1739794a(28) =3605077a(29) =7457977