[tex]a = b + 2[/tex]
[tex]pt. \: a = 2 = > b = 0[/tex]
[tex]pt. \: a = 3 = > b = 1[/tex]
[tex]pt. \: a = 4 = > b = 2[/tex]
[tex]pt. \: a = 5 = > b = 3[/tex]
[tex]pt. \: a = 6 = > b = 4[/tex]
[tex]pt. \: a = 7 = > b = 5[/tex]
[tex]pt. \: a = 8 = > b = 6[/tex]
[tex]pt. \: a = 9 = > b = 7[/tex]
[tex] \overline{ab}\:: \: 20,31,42,53,64,75,86,97.[/tex]