Numbers k such that 50*R_k + 3 is prime, where R_k = 11...1 is the repunit (A002275) of length k.
A056685
Numbers k such that 50*R_k + 3 is prime, where R_k = 11...1 is the repunit (A002275) of length k.
Terms
- a(0) =0a(1) =1a(2) =7a(3) =25a(4) =65a(5) =73a(6) =232a(7) =472a(8) =539a(9) =2773a(10) =64714
External references
- oeis: A056685