Numbers n such that string 5,5 occurs in the base 10 representation of n but not of n-1.

Terms

a(0) =55a(1) =155a(2) =255a(3) =355a(4) =455a(5) =550a(6) =655a(7) =755a(8) =855a(9) =955a(10) =1055a(11) =1155a(12) =1255a(13) =1355a(14) =1455a(15) =1550a(16) =1655a(17) =1755a(18) =1855a(19) =1955a(20) =2055a(21) =2155a(22) =2255a(23) =2355a(24) =2455a(25) =2550a(26) =2655a(27) =2755a(28) =2855a(29) =2955