Prime divisors of solutions to 10^n == 1 (mod n).

Terms

a(0) =3a(1) =37a(2) =163a(3) =757a(4) =1999a(5) =5477a(6) =8803a(7) =9397a(8) =13627a(9) =15649a(10) =36187a(11) =40879a(12) =62597a(13) =106277a(14) =147853a(15) =161839a(16) =215893a(17) =231643a(18) =281683a(19) =295759a(20) =313471a(21) =333667a(22) =338293a(23) =478243a(24) =490573a(25) =607837a(26) =647357a(27) =743933a(28) =988643a(29) =1014877