A093169 Primes of the form 50*R_k + 7, where R_k is the repunit (A002275) of length k.

7, 557, 5557, 555557, 5555555557, 555555555555557, 5555555555555555555557, 5555555555555555555555555555555555555555555555555555555555555555555555555555555555555557

Offset: 1

Author

Rick L. Shepherd, Mar 26 2004

Keywords

• nonn

Comments

Primes of the form (5*10^k + 13)/9. - Vincenzo Librandi, Nov 16 2010

Links

• Makoto Kamada, Prime numbers of the form 55...557.
• Index entries for primes involving repunits

Crossrefs

Cf. A056686 (corresponding k).