Primes of the form 7*10^k + 3*R_k, where R_k is the repunit (A002275) of length k.

A093675

Primes of the form 7*10^k + 3*R_k, where R_k is the repunit (A002275) of length k.

Terms

    a(0) =7a(1) =73a(2) =733a(3) =7333a(4) =733333

External references