Numbers whose base-4 representation has the same number of 0's, 1's and 3's.

Terms

a(0) =2a(1) =10a(2) =19a(3) =28a(4) =42a(5) =49a(6) =52a(7) =75a(8) =78a(9) =99a(10) =108a(11) =114a(12) =120a(13) =135a(14) =141a(15) =147a(16) =156a(17) =170a(18) =177a(19) =180a(20) =198a(21) =201a(22) =210a(23) =216a(24) =225a(25) =228a(26) =299a(27) =302a(28) =314a(29) =395