Numbers whose base-9 representation has the same nonzero number of 0's and 3's.

Terms

a(0) =27a(1) =84a(2) =108a(3) =165a(4) =189a(5) =244a(6) =245a(7) =247a(8) =248a(9) =249a(10) =250a(11) =251a(12) =252a(13) =261a(14) =279a(15) =288a(16) =297a(17) =306a(18) =315a(19) =327a(20) =351a(21) =408a(22) =432a(23) =489a(24) =513a(25) =570a(26) =594a(27) =651a(28) =675a(29) =741