Numbers with exactly four distinct base-8 digits.

Terms

a(0) =531a(1) =532a(2) =533a(3) =534a(4) =535a(5) =538a(6) =540a(7) =541a(8) =542a(9) =543a(10) =546a(11) =547a(12) =549a(13) =550a(14) =551a(15) =554a(16) =555a(17) =556a(18) =558a(19) =559a(20) =562a(21) =563a(22) =564a(23) =565a(24) =567a(25) =570a(26) =571a(27) =572a(28) =573a(29) =574