Numbers whose base-7 representation has the same nonzero number of 3's and 4's.

Terms

a(0) =25a(1) =31a(2) =74a(3) =80a(4) =123a(5) =129a(6) =151a(7) =158a(8) =165a(9) =175a(10) =176a(11) =177a(12) =180a(13) =181a(14) =186a(15) =193a(16) =199a(17) =206a(18) =213a(19) =217a(20) =218a(21) =219a(22) =222a(23) =223a(24) =234a(25) =241a(26) =270a(27) =276a(28) =319a(29) =325