Numbers whose base-7 representation has one more 0 than 6's.

Terms

a(0) =7a(1) =14a(2) =21a(3) =28a(4) =35a(5) =50a(6) =51a(7) =52a(8) =53a(9) =54a(10) =56a(11) =63a(12) =70a(13) =77a(14) =84a(15) =99a(16) =100a(17) =101a(18) =102a(19) =103a(20) =105a(21) =112a(22) =119a(23) =126a(24) =133a(25) =148a(26) =149a(27) =150a(28) =151a(29) =152