Numbers having four 7's in base 9.

Terms

a(0) =5740a(1) =12301a(2) =18862a(3) =25423a(4) =31984a(5) =38545a(6) =45106a(7) =46564a(8) =47293a(9) =48022a(10) =48751a(11) =49480a(12) =50209a(13) =50938a(14) =51100a(15) =51181a(16) =51262a(17) =51343a(18) =51424a(19) =51505a(20) =51586a(21) =51604a(22) =51613a(23) =51622a(24) =51631a(25) =51640a(26) =51649a(27) =51658a(28) =51660a(29) =51661