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Primes of the form m*p^2 + 1, where p is prime and m <= p^2.
1

%I #7 May 13 2013 01:54:21

%S 5,13,17,19,37,73,101,151,197,251,401,491,601,677,727,883,1373,1453,

%T 1471,1667,2029,2179,2663,3389,3469,3631,3719,4057,4357,4733,5477,

%U 6359,6761,7019,8093,8713,8837,9127,9439,9803,9923,10093,10141,10831,10891,11617,11831,12101,12343

%N Primes of the form m*p^2 + 1, where p is prime and m <= p^2.

%C Not known to be infinite, but see the Matomäki link.

%H Charles R Greathouse IV, <a href="/A212287/b212287.txt">Table of n, a(n) for n = 1..10000</a>

%H Kaisa Matomäki, <a href="http://users.utu.fi/ksmato/papers/Primesaq2p1.pdf">A note on primes of the form p = aq^2 + 1</a>, Acta Arith. 137 (2009), pp. 133-137.

%e 13 is a member since 13 = 3 * 2^2 + 1 with 3 <= 2^2 and 3 is prime.

%o (PARI) list(lim)=my(v=List(),t);lim=lim\1-.5;forprime(p=2,sqrt(lim), for(a=1,min(lim\p^2,p^2),if(isprime(t=a*p^2+1),listput(v,t))));vecsort(Vec(v),,8)

%Y Cf. A028916, A173587.

%K nonn

%O 1,1

%A _Charles R Greathouse IV_, Jun 13 2012