Numbers with a single 0 in their base 4 expansion.

Terms

a(0) =0a(1) =4a(2) =8a(3) =12a(4) =17a(5) =18a(6) =19a(7) =20a(8) =24a(9) =28a(10) =33a(11) =34a(12) =35a(13) =36a(14) =40a(15) =44a(16) =49a(17) =50a(18) =51a(19) =52a(20) =56a(21) =60a(22) =69a(23) =70a(24) =71a(25) =73a(26) =74a(27) =75a(28) =77a(29) =78