Numbers with exactly 3 2's in their base 4 expansion.

Terms

a(0) =42a(1) =106a(2) =138a(3) =154a(4) =162a(5) =166a(6) =168a(7) =169a(8) =171a(9) =174a(10) =186a(11) =234a(12) =298a(13) =362a(14) =394a(15) =410a(16) =418a(17) =422a(18) =424a(19) =425a(20) =427a(21) =430a(22) =442a(23) =490a(24) =522a(25) =538a(26) =546a(27) =550a(28) =552a(29) =553