Numbers k such that R_(k+2) - 10^k is prime, where R_k = 11...1 is the repunit (A002275) of length k.
A256912
Numbers k such that R_(k+2) - 10^k is prime, where R_k = 11...1 is the repunit (A002275) of length k.
Terms
- a(0) =1a(1) =3a(2) =4a(3) =7a(4) =10a(5) =16a(6) =66a(7) =138a(8) =5839a(9) =23898a(10) =112098
External references
- oeis: A256912