Numbers k such that (10^k)^2 + 5*(10^k) - 1 is prime.
A108240
Numbers k such that (10^k)^2 + 5*(10^k) - 1 is prime.
Terms
- a(0) =0a(1) =1a(2) =2a(3) =7a(4) =45a(5) =54a(6) =60a(7) =99a(8) =195a(9) =271a(10) =476a(11) =1491a(12) =2713a(13) =8155
External references
- oeis: A108240