Numbers k with digits 5 and 9 only.

Terms

a(0) =5a(1) =9a(2) =55a(3) =59a(4) =95a(5) =99a(6) =555a(7) =559a(8) =595a(9) =599a(10) =955a(11) =959a(12) =995a(13) =999a(14) =5555a(15) =5559a(16) =5595a(17) =5599a(18) =5955a(19) =5959a(20) =5995a(21) =5999a(22) =9555a(23) =9559a(24) =9595a(25) =9599a(26) =9955a(27) =9959a(28) =9995a(29) =9999