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

Terms

a(0) =6a(1) =13a(2) =20a(3) =27a(4) =34a(5) =41a(6) =43a(7) =44a(8) =45a(9) =46a(10) =47a(11) =62a(12) =69a(13) =76a(14) =83a(15) =90a(16) =92a(17) =93a(18) =94a(19) =95a(20) =96a(21) =111a(22) =118a(23) =125a(24) =132a(25) =139a(26) =141a(27) =142a(28) =143a(29) =144