Primes of the form 6*10^k + R_k, where R_k is the repunit (A002275) of length k.

A093631

Primes of the form 6*10^k + R_k, where R_k is the repunit (A002275) of length k.

Terms

    a(0) =61a(1) =611111a(2) =61111111

External references