Numbers whose base-6 representation has the same number of 0's and 1's.

Terms

a(0) =2a(1) =3a(2) =4a(3) =5a(4) =6a(5) =14a(6) =15a(7) =16a(8) =17a(9) =20a(10) =21a(11) =22a(12) =23a(13) =26a(14) =27a(15) =28a(16) =29a(17) =32a(18) =33a(19) =34a(20) =35a(21) =38a(22) =39a(23) =40a(24) =41a(25) =48a(26) =54a(27) =60a(28) =66a(29) =73