Numbers n such that 6*10^n + R_n + 6 is prime, where R_n = 11...1 is the repunit (A002275) of length n.
A103028
Numbers n such that 6*10^n + R_n + 6 is prime, where R_n = 11...1 is the repunit (A002275) of length n.
Terms
- a(0) =1a(1) =2a(2) =32a(3) =43a(4) =973a(5) =1195a(6) =4471a(7) =5684a(8) =7988a(9) =46885
External references
- oeis: A103028