Numbers whose base-9 representation has the same nonzero number of 3's and 6's.

Terms

a(0) =33a(1) =57a(2) =114a(3) =138a(4) =195a(5) =219a(6) =249a(7) =258a(8) =267a(9) =285a(10) =294a(11) =297a(12) =298a(13) =299a(14) =301a(15) =302a(16) =304a(17) =305a(18) =312a(19) =321a(20) =357a(21) =381a(22) =438a(23) =462a(24) =489a(25) =498a(26) =507a(27) =513a(28) =514a(29) =515