Palindromes arising in A083457.

Terms

a(0) =0a(1) =3a(2) =7a(3) =9999a(4) =242a(5) =999999a(6) =9999999a(7) =99999999a(8) =999999999a(9) =9999999999a(10) =99999999999a(11) =999999999999