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A124518
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Numbers k such that 10k-1 and 10k+1 are twin primes.
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10
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3, 6, 15, 18, 24, 27, 42, 57, 60, 66, 81, 102, 105, 123, 129, 132, 162, 195, 213, 231, 234, 255, 273, 279, 297, 300, 312, 330, 333, 336, 339, 354, 393, 402, 405, 423, 426, 465, 480, 501, 510, 528, 552, 564, 585, 588, 609, 627, 630, 636, 645, 657, 666, 669, 678
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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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MAPLE
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select(t -> isprime(10*t+1) and isprime(10*t-1), [seq(i, i=3..1000, 3)]); # Robert Israel, Apr 07 2019
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MATHEMATICA
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Select[Range[678], And @@ PrimeQ[{-1, 1} + 10# ] &] (* Ray Chandler, Nov 16 2006 *)
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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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