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.
A103084
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) =1a(1) =2a(2) =7a(3) =44a(4) =56a(5) =338a(6) =1211a(7) =2693a(8) =3536a(9) =3917a(10) =3974a(11) =4046a(12) =6961a(13) =23771a(14) =69656
External references
- oeis: A103084