Numbers with no 2's in their base 4 expansion.

Terms

a(0) =0a(1) =1a(2) =3a(3) =4a(4) =5a(5) =7a(6) =12a(7) =13a(8) =15a(9) =16a(10) =17a(11) =19a(12) =20a(13) =21a(14) =23a(15) =28a(16) =29a(17) =31a(18) =48a(19) =49a(20) =51a(21) =52a(22) =53a(23) =55a(24) =60a(25) =61a(26) =63a(27) =64a(28) =65a(29) =67