When expressed in base 2 and then interpreted in base 9, is a multiple of the original number.

Terms

a(0) =0a(1) =1a(2) =6a(3) =7a(4) =17a(5) =18a(6) =30a(7) =34a(8) =49a(9) =60a(10) =90a(11) =102a(12) =108a(13) =119a(14) =126a(15) =180a(16) =203a(17) =204a(18) =210a(19) =238a(20) =269a(21) =306a(22) =420a(23) =510a(24) =538a(25) =540a(26) =612a(27) =630a(28) =882a(29) =1020