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A079796
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Primes p such that (3*p)^2 + p^2 + 3^2 and (3*p)^2 - p^2 - 3^2 are both prime.
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1
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7, 29, 83, 181, 197, 337, 601, 631, 1303, 1847, 2029, 3023, 3109, 3359, 4591, 4649, 4831, 6397, 6791, 7489, 7559, 7573, 7951, 8609, 8933, 9857, 10151, 10457, 10501, 10709, 11467, 11633, 12011, 12377, 12641, 12739, 13469, 14197, 14449, 14519
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OFFSET
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1,1
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COMMENTS
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Also called nonomatic primes. There is probably an infinity of them. There seems to be no prime number with a similar property using 5 or a larger factor in the polynomials.
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LINKS
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EXAMPLE
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a(2) = 29 since (3*29)^2 + 29^2 + 3^2 = 8419 and (3*29)^2 - 29^2 - 3^2 = 6719 are both primes.
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MATHEMATICA
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Select[Prime@Range[1, 2000], PrimeQ[9 #^2 + #^2 + 9] && PrimeQ[9 #^2 - #^2 - 9] &] (* Vincenzo Librandi, Oct 18 2012 *)
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PROG
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(Magma) [p: p in PrimesUpTo(15000)| IsPrime( (3*p)^2 + p^2 + 3^2) and IsPrime((3*p)^2 - p^2 - 3^2)]; // Vincenzo Librandi, Oct 18 2012
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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