Numbers whose base-7 representation has the same nonzero number of 3's and 6's.

Terms

a(0) =27a(1) =45a(2) =76a(3) =94a(4) =125a(5) =143a(6) =153a(7) =160a(8) =167a(9) =181a(10) =188a(11) =189a(12) =190a(13) =191a(14) =193a(15) =194a(16) =223a(17) =241a(18) =272a(19) =290a(20) =297a(21) =304a(22) =311a(23) =315a(24) =316a(25) =317a(26) =319a(27) =320a(28) =325a(29) =332