A096213 - OEIS

%I #5 May 22 2014 15:02:08

%S 1000009999,10000099999,1000009999999999,100000999999999999999999,

%T 100000999999999999999999999999,1000009999999999999999999999999,

%U 10000099999999999999999999999999999999999999999999999999999999999999999999

%N Primes of the form 10^n + 10^(n-5) - 1.

%t Select[Table[10^n+10^(n-5)-1,{n,80}],PrimeQ] (* _Harvey P. Dale_, May 22 2014 *)

%o (PARI) f(n,z) = for(x=z,n,y=10^x+10^(x-z)-1;if(ispseudoprime(y),print1(y",")))

%K nonn

%O 1,1

%A _Cino Hilliard_, Jul 28 2004