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A067664
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Numbers n such that n^2 + 1 and n^2 + n + 1 are primes.
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1
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1, 2, 6, 14, 20, 24, 54, 66, 90, 110, 150, 176, 206, 236, 314, 584, 644, 686, 696, 860, 864, 890, 920, 950, 960, 1070, 1146, 1274, 1314, 1340, 1434, 1440, 1494, 1566, 1616, 1644, 1676, 1700, 1716, 1970, 1974, 2054, 2064, 2136, 2360, 2430, 2456, 2604, 2646
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OFFSET
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1,2
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COMMENTS
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All the terms are even numbers except for a(1) = 1. - Metin Sariyar, Nov 23 2019
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LINKS
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MATHEMATICA
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Join[{1}, Select[Range[2, 10^6, 2], PrimeQ[#^2+1]&&PrimeQ[#^2+#+1]&]] (* Metin Sariyar, Nov 23 2019 *)
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PROG
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(Magma) [n: n in [0..10000]| IsPrime(n^2+1) and IsPrime(n^2+n+1)] // Vincenzo Librandi, Aug 07 2010
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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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