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A267378
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Primes of the form k^4 - k^2 + 7.
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0
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7, 19, 79, 607, 9907, 20599, 65287, 104659, 129967, 331207, 1047559, 1184839, 1872799, 3746167, 4098607, 6762607, 7308919, 11313139, 20146639, 21376759, 28392919, 43040167, 54693427, 59961799, 84925447, 104050207, 108232819, 131068159, 168883027, 187375039
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OFFSET
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1,1
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COMMENTS
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All terms == 7 or 19 (mod 30). (End)
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LINKS
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EXAMPLE
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k = 5: 5^4-5^2+7=607 (is prime).
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MAPLE
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select(isprime, [seq(x^4-x^2+7, x=1..1000)]); # Robert Israel, Jan 18 2016
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MATHEMATICA
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PROG
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(Magma) [a: n in [1..150] | IsPrime(a) where a is n^4-n^2+7]; // Vincenzo Librandi, Jan 15 2016
(PARI) lista(nn) = for(n=1, nn, if(ispseudoprime(p=n^4-n^2+7), print1(p, ", "))); \\ Altug Alkan, Jan 15 2016
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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