Numbers whose base-4 representation contains no 0's and exactly four 2's.

Terms

a(0) =170a(1) =426a(2) =618a(3) =666a(4) =678a(5) =681a(6) =683a(7) =686a(8) =698a(9) =746a(10) =938a(11) =1450a(12) =1642a(13) =1690a(14) =1702a(15) =1705a(16) =1707a(17) =1710a(18) =1722a(19) =1770a(20) =1962a(21) =2410a(22) =2458a(23) =2470a(24) =2473a(25) =2475a(26) =2478a(27) =2490a(28) =2538a(29) =2650