Numbers k such that 5*10^(2*k) + 5*10^k + 1 is prime.
A309740
Numbers k such that 5*10^(2*k) + 5*10^k + 1 is prime.
Terms
- a(0) =0a(1) =3a(2) =5a(3) =301a(4) =13817a(5) =15259
External references
- oeis: A309740
A309740
Numbers k such that 5*10^(2*k) + 5*10^k + 1 is prime.