Primes of the form 30*R_k + 7, where R_k is the repunit (A002275) of length k.

A093168

Primes of the form 30*R_k + 7, where R_k is the repunit (A002275) of length k.

Terms

    a(0) =7a(1) =37a(2) =337a(3) =333337

External references