Numbers whose base-6 representation has the same nonzero number of 0's and 3's.

Terms

a(0) =18a(1) =39a(2) =54a(3) =75a(4) =90a(5) =109a(6) =110a(7) =112a(8) =113a(9) =114a(10) =120a(11) =132a(12) =138a(13) =147a(14) =162a(15) =183a(16) =198a(17) =225a(18) =231a(19) =235a(20) =236a(21) =238a(22) =239a(23) =243a(24) =249a(25) =255a(26) =270a(27) =291a(28) =306a(29) =325