Numbers k such that 3*10^k + R_k + 6 is prime, where R_k = 11...1 is the repunit (A002275) of length k.
A101393
Numbers k such that 3*10^k + R_k + 6 is prime, where R_k = 11...1 is the repunit (A002275) of length k.
Terms
- a(0) =1a(1) =2a(2) =218a(3) =692a(4) =1805a(5) =2207a(6) =2873a(7) =59135
External references
- oeis: A101393