A158711 Primes p such that p1=Floor[p/2]+p is prime and p2=Floor[p1/2]+p1 is prime.

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

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Mar 24 2009

Keywords

• nonn

Crossrefs

Cf. A158708, A158709, A158710

Programs

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 *)

Extensions

Definition corrected by Harvey P. Dale, Apr 21 2016