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A158711
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Primes p such that p1=Floor[p/2]+p is prime and p2=Floor[p1/2]+p1 is prime.
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8
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73, 233, 281, 409, 449, 569, 953, 1129, 1193, 1409, 1481, 2473, 2801, 3041, 3209, 3329, 3761, 3833, 3881, 4049, 4153, 5113, 5441, 6673, 7193, 9601, 9689, 10433, 10889, 11161, 11321, 11369, 11593, 11953, 12041, 12113, 12329, 12713, 12721
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OFFSET
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1,1
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LINKS
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MATHEMATICA
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lst={}; Do[p=Prime[n]; If[PrimeQ[p=Floor[p/2]+p], If[PrimeQ[p=Floor[p/2]+p], AppendTo[lst, Prime[n]]]], {n, 7!}]; lst
prQ[n_]:=Module[{p1=Floor[n/2]+n}, AllTrue[{p1, Floor[p1/2]+p1}, PrimeQ]]; Select[Prime[Range[1600]], prQ] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Apr 21 2016 *)
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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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STATUS
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approved
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