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A087697
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Numbers k such that k + 7 and k - 7 are both prime.
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13
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10, 12, 24, 30, 36, 54, 60, 66, 90, 96, 120, 144, 156, 174, 186, 204, 234, 264, 270, 276, 300, 324, 360, 366, 390, 426, 450, 456, 516, 564, 570, 594, 600, 606, 624, 654, 666, 684, 726, 750, 780, 804, 816, 846, 870, 960, 984, 990
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OFFSET
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1,1
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LINKS
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MAPLE
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select(t -> isprime(t+7) and isprime(t-7), [seq(i, i=8..1000, 2)]); # Robert Israel, Jul 22 2018
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MATHEMATICA
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Rest[Select[Range[1000], PrimeQ[# - 7] && PrimeQ[# + 7] &]] (* Vincenzo Librandi, Jul 23 2018 *)
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PROG
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(PARI) isok(n) = isprime(n-7) && isprime(n+7); \\ Michel Marcus, Jul 23 2018
(Magma) [n: n in [5..1000] | IsPrime(n-7) and IsPrime(n+7)]; // Vincenzo Librandi, Jul 23 2018
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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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STATUS
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approved
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