Numbers k such that k*10^k + 1 is prime.

A007647

Numbers k such that k*10^k + 1 is prime.

Terms

    a(0) =1a(1) =3a(2) =9a(3) =21a(4) =363a(5) =2161a(6) =4839a(7) =49521a(8) =105994a(9) =207777

External references