Primes of the form 80*R_k + 7, where R_k is the repunit (A002275) of length k.

A093171

Primes of the form 80*R_k + 7, where R_k is the repunit (A002275) of length k.

Terms

    a(0) =7a(1) =887a(2) =8887a(3) =888887a(4) =888888887a(5) =888888888887

External references