Numbers whose base-4 representation has one more 0 than 3's.

Terms

a(0) =4a(1) =8a(2) =17a(3) =18a(4) =20a(5) =24a(6) =33a(7) =34a(8) =36a(9) =40a(10) =48a(11) =67a(12) =69a(13) =70a(14) =73a(15) =74a(16) =76a(17) =81a(18) =82a(19) =84a(20) =88a(21) =97a(22) =98a(23) =100a(24) =104a(25) =112a(26) =131a(27) =133a(28) =134a(29) =137