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A158711 Primes p such that p1=Floor[p/2]+p is prime and p2=Floor[p1/2]+p1 is prime. 8
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..39.

MATHEMATICA

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 *)

CROSSREFS

Cf. A158708, A158709, A158710

Sequence in context: A141909 A296187 A142517 * A140039 A201715 A071392

Adjacent sequences:  A158708 A158709 A158710 * A158712 A158713 A158714

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, Mar 24 2009

EXTENSIONS

Definition corrected by Harvey P. Dale, Apr 21 2016

STATUS

approved

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Last modified March 29 04:13 EDT 2020. Contains 333105 sequences. (Running on oeis4.)