Indices of prime repunits: numbers k such that 11...111 (with k 1's) = (10^k - 1)/9 is prime.
A004023
Indices of prime repunits: numbers k such that 11...111 (with k 1's) = (10^k - 1)/9 is prime.
Terms
- a(0) =2a(1) =19a(2) =23a(3) =317a(4) =1031a(5) =49081a(6) =86453a(7) =109297a(8) =270343a(9) =5794777a(10) =8177207
External references
- oeis: A004023