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%I #6 Oct 01 2013 17:58:00
%S 10009,1000999,10009999999999,10009999999999999999999999999999999999,
%T 10009999999999999999999999999999999999999999999999999999999999999,
%U 10009999999999999999999999999999999999999999999999999999999999999999999999999
%N Primes of the form 10^n + 10^(n-3) - 1.
%H Vincenzo Librandi, <a href="/A096211/b096211.txt">Table of n, a(n) for n = 1..10</a>
%t t={};Do[m=n;p=10^n+10^(n-3)-1;If[PrimeQ[p],AppendTo[t,p]],{n,300}];t (* _Vincenzo Librandi_, Jul 17 2012 *)
%o (PARI) f(n,z) = for(x=z,n,y=10^x+10^(x-z)-1;if(ispseudoprime(y),print1(y",")))
%K nonn,easy
%O 1,1
%A _Cino Hilliard_, Jul 28 2004