Numbers with a single 2 in their base 4 expansion.

Terms

a(0) =2a(1) =6a(2) =8a(3) =9a(4) =11a(5) =14a(6) =18a(7) =22a(8) =24a(9) =25a(10) =27a(11) =30a(12) =32a(13) =33a(14) =35a(15) =36a(16) =37a(17) =39a(18) =44a(19) =45a(20) =47a(21) =50a(22) =54a(23) =56a(24) =57a(25) =59a(26) =62a(27) =66a(28) =70a(29) =72