Numbers whose base-4 representation contains exactly three 1's and three 2's.

Terms

a(0) =1386a(1) =1434a(2) =1446a(3) =1449a(4) =1626a(5) =1638a(6) =1641a(7) =1686a(8) =1689a(9) =1701a(10) =2394a(11) =2406a(12) =2409a(13) =2454a(14) =2457a(15) =2469a(16) =2646a(17) =2649a(18) =2661a(19) =2709a(20) =4458a(21) =4506a(22) =4518a(23) =4521a(24) =4698a(25) =4710a(26) =4713a(27) =4758a(28) =4761a(29) =4773