Numbers whose base-8 representation has the same nonzero number of 4's and 7's.

Terms

a(0) =39a(1) =60a(2) =103a(3) =124a(4) =167a(5) =188a(6) =231a(7) =252a(8) =263a(9) =271a(10) =279a(11) =287a(12) =303a(13) =311a(14) =312a(15) =313a(16) =314a(17) =315a(18) =317a(19) =318a(20) =359a(21) =380a(22) =423a(23) =444a(24) =452a(25) =460a(26) =468a(27) =476a(28) =480a(29) =481