Numbers having two 5's in base 10.

Terms

a(0) =55a(1) =155a(2) =255a(3) =355a(4) =455a(5) =505a(6) =515a(7) =525a(8) =535a(9) =545a(10) =550a(11) =551a(12) =552a(13) =553a(14) =554a(15) =556a(16) =557a(17) =558a(18) =559a(19) =565a(20) =575a(21) =585a(22) =595a(23) =655a(24) =755a(25) =855a(26) =955a(27) =1055a(28) =1155a(29) =1255