Numbers k such that 2*R_k + 3*10^k + 1 is prime, where R_k = 11...11 is the repunit (A002275) of length k.

A259129

Numbers k such that 2*R_k + 3*10^k + 1 is prime, where R_k = 11...11 is the repunit (A002275) of length k.

Terms

    a(0) =6a(1) =8a(2) =894a(3) =1524a(4) =3036a(5) =21156

External references