Primes of the form 10*R_k + 9, where R_k is the repunit (A002275) of length k.
A093400
Primes of the form 10*R_k + 9, where R_k is the repunit (A002275) of length k.
Terms
- a(0) =19a(1) =11119a(2) =111119a(3) =11111119
External references
- oeis: A093400