Numbers n such that string 2,1 occurs in the base 9 representation of n but not of n+1.

Terms

a(0) =19a(1) =100a(2) =179a(3) =181a(4) =262a(5) =343a(6) =424a(7) =505a(8) =586a(9) =667a(10) =748a(11) =829a(12) =908a(13) =910a(14) =991a(15) =1072a(16) =1153a(17) =1234a(18) =1315a(19) =1396a(20) =1477a(21) =1619a(22) =1637a(23) =1639a(24) =1720a(25) =1801a(26) =1882a(27) =1963a(28) =2044a(29) =2125