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Smallest prime q such that p^q-2 is prime where p ranges over the set of primes numbers.
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%I #2 Oct 01 2013 18:07:49

%S 2,2,2,2,2,2,2,3,2,2,2,2,3,2,2,2,2,3,2,2,2,3,149,2,5,2,7,2,2,5,2,2,3,

%T 2,5,3,89,2,2,2,13,2,3,367,2,17,3,2,2,3,2,2,2,2,439,2,61,127,2,2,3,2,

%U 37,2,3,2,2,2,2,2,2,2

%N Smallest prime q such that p^q-2 is prime where p ranges over the set of primes numbers.

%e 2^2-2 = 2 prime so a(1)=2, 3^2-2= 7 prime a(2)=2. For q=2,3,5, 199^q-2 is not

%e prime. For q=7, 199^7-2 = 12358664279161397 prime so a(27)=7.

%o (PARI) g2(n) = forprime(x=2,n,y=g(1000,x);if(y>0,print1(y",")))

%o g(n, m) = p1=0;forprime(p=2,n,y=m^p-2;if(ispseudoprime(y),p1=p;break));p1

%K nonn

%O 2,1

%A _Cino Hilliard_, Nov 13 2008