Numbers whose base-7 representation has 2 more 0's than 6's.

Terms

a(0) =49a(1) =98a(2) =147a(3) =196a(4) =245a(5) =344a(6) =345a(7) =346a(8) =347a(9) =348a(10) =350a(11) =357a(12) =364a(13) =371a(14) =378a(15) =392a(16) =441a(17) =490a(18) =539a(19) =588a(20) =687a(21) =688a(22) =689a(23) =690a(24) =691a(25) =693a(26) =700a(27) =707a(28) =714a(29) =721