Divisors of 10^11 - 1.

Terms

a(0) =1a(1) =3a(2) =9a(3) =21649a(4) =64947a(5) =194841a(6) =513239a(7) =1539717a(8) =4619151a(9) =11111111111a(10) =33333333333a(11) =99999999999