Numbers whose base-7 representation has the same nonzero number of 0's and 5's.

Terms

a(0) =35a(1) =54a(2) =84a(3) =103a(4) =133a(5) =152a(6) =182a(7) =201a(8) =231a(9) =246a(10) =247a(11) =248a(12) =249a(13) =251a(14) =252a(15) =259a(16) =266a(17) =273a(18) =287a(19) =299a(20) =329a(21) =355a(22) =362a(23) =369a(24) =376a(25) =379a(26) =380a(27) =381a(28) =382a(29) =384