Numbers whose base-9 representation has the same nonzero number of 1's and 3's.

Terms

a(0) =12a(1) =28a(2) =84a(3) =102a(4) =108a(5) =110a(6) =112a(7) =113a(8) =114a(9) =115a(10) =116a(11) =120a(12) =129a(13) =138a(14) =147a(15) =156a(16) =174a(17) =190a(18) =244a(19) =252a(20) =254a(21) =256a(22) =257a(23) =258a(24) =259a(25) =260a(26) =262a(27) =280a(28) =289a(29) =298