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A163630
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Numbers such that the two adjacent integers are a prime and 7 times a prime.
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1
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20, 22, 36, 48, 78, 90, 132, 162, 258, 330, 372, 468, 498, 510, 678, 708, 720, 750, 762, 888, 918, 972, 1098, 1170, 1212, 1380, 1560, 1602, 1758, 1800, 1980, 2052, 2178, 2220, 2358, 2442, 2472, 2610, 2682, 2778, 2862
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OFFSET
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1,1
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LINKS
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EXAMPLE
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MATHEMATICA
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prQ[n_] := Module[{a = n - 1, b = n + 1}, (PrimeQ[a] && PrimeQ[b/7]) || (PrimeQ[b] && PrimeQ[a/7])]; Select[Range[5000], prQ] (* G. C. Greubel, Jul 30 2017 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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20 inserted, 62 removed, 90 added etc. by R. J. Mathar, Aug 07 2009
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STATUS
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approved
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