Numbers k such that 3*R_k + 10^k - 2 is prime, where R_k = 11...11 is the repunit (A002275) of length k.
A259050
Numbers k such that 3*R_k + 10^k - 2 is prime, where R_k = 11...11 is the repunit (A002275) of length k.
Terms
- a(0) =1a(1) =2a(2) =4a(3) =6a(4) =94a(5) =160a(6) =360a(7) =1470a(8) =2898a(9) =3094a(10) =3112a(11) =15698a(12) =17956a(13) =42262a(14) =111032a(15) =249550
External references
- oeis: A259050