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A330438
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Numbers k such that k^2-2 and k^3-2 are prime.
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1
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9, 15, 19, 27, 37, 121, 135, 145, 211, 217, 259, 265, 267, 279, 355, 357, 387, 391, 435, 489, 525, 561, 615, 621, 727, 951, 987, 1029, 1119, 1141, 1177, 1251, 1287, 1357, 1435, 1491, 1561, 1617, 1717, 1785, 1819, 1839, 1875, 1909, 1989, 2001, 2077, 2107, 2211
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OFFSET
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1,1
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COMMENTS
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LINKS
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EXAMPLE
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a(1) = 9: 9^2 - 2 = 79; 9^3 - 2 = 727; both results are prime.
a(2) = 15: 15^2 - 2 = 223; 15^3 - 2 = 3373; both results are prime.
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MAPLE
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filter:= k -> isprime(k^2-2) and isprime(k^3-2):
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MATHEMATICA
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Select[Range[10000], PrimeQ[#^3 - 2] && PrimeQ[#^2 - 2] &]
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PROG
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(Magma) [n : n in [1 .. 100] | IsPrime (n^2 - 2) and IsPrime (n^3 - 2)];
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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