Numbers n such that 8*10^n + 5*R_n + 2 is prime, where R_n = 11...1 is the repunit (A002275) of length n.
A103085
Numbers n such that 8*10^n + 5*R_n + 2 is prime, where R_n = 11...1 is the repunit (A002275) of length n.
Terms
- a(0) =2a(1) =8a(2) =1056a(3) =19835a(4) =20018a(5) =36464a(6) =81606
External references
- oeis: A103085