Primes of the form 50*R_k + 7, where R_k is the repunit (A002275) of length k.
A093169
Primes of the form 50*R_k + 7, where R_k is the repunit (A002275) of length k.
Terms
- a(0) =7a(1) =557a(2) =5557a(3) =555557a(4) =5555555557
External references
- oeis: A093169