A172998 Numbers n such that 10^4n + 10^3n - 10^n - 3 is prime.

1, 2, 3, 4, 372

Offset: 1

Author

James G. Merickel, Feb 07 2010

Keywords

• nonn

Comments

Corresponds to the numbers 10987, 100999897, 1000999998997, 10000999999989997, ...

Programs

Mathematica

fQ[n_] := PrimeQ[10^(4 n) + 10^(3 n) - 10^n - 3]; k = 1; lst = {}; While[k < 3300, If[ fQ@k, AppendTo[lst, k]]; k++ ]; lst (* Robert G. Wilson v, Feb 15 2010 *)

PARI

is(n)=ispseudoprime(10^4*n+10^3*n-10^n-3) \\ Charles R Greathouse IV, Jun 13 2017