Numbers whose base-12 representation has the same nonzero number of 4's and 7's.

Terms

a(0) =55a(1) =88a(2) =199a(3) =232a(4) =343a(5) =376a(6) =487a(7) =520a(8) =583a(9) =595a(10) =607a(11) =619a(12) =643a(13) =655a(14) =660a(15) =661a(16) =662a(17) =663a(18) =665a(19) =666a(20) =668a(21) =669a(22) =670a(23) =671a(24) =679a(25) =691a(26) =703a(27) =715a(28) =775a(29) =808