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A152295
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Primes of the form : (p-n)/(n+1)=prime and (n+1)*p+n=prime. n=5.
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3
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17, 71, 83, 107, 191, 227, 251, 263, 431, 443, 479, 503, 587, 827, 839, 911, 983, 1091, 1151, 1163, 1187, 1619, 1667, 1847, 1907, 2087, 2243, 2459, 2591, 3023, 3467, 4463, 4871, 4943, 5471, 5519, 5651, 5807, 5903, 6131, 6203, 6299, 6311, 6563, 6983, 7127
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OFFSET
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1,1
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COMMENTS
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This is the general form : (p-n)/(n+1)=primeand(n+1)*p+n=prime; 'Safe' primes and'Sophie Germain' primes just one part of this general form; If n=1 then we got'Safe' primes and'Sophie Germain' primes.
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LINKS
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MATHEMATICA
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lst={}; n=5; Do[p=Prime[k]; If[PrimeQ[(p-n)/(n+1)]&&PrimeQ[(n+1)*p+n], AppendTo[lst, p]], {k, 7!}]; lst
Select[Prime[Range[1000]], AllTrue[{(#-5)/6, 6#+5}, PrimeQ]&] (* This program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Jul 29 2014 *)
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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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