A158719 Primes p such that p1 = floor(p/2)+p is not prime and p2 = ceiling(p/2)+p is not prime, p3 = floor(p1/2)+p1 is not prime and p5 = ceiling(p1/2)+p1 is not prime, p4 = floor(p2/2)+p2 is not prime and p6 = ceiling(p2/2)+p2 is not prime.

83, 97, 113, 227, 229, 251, 269, 271, 277, 283, 313, 317, 331, 353, 389, 397, 419, 433, 457, 463, 491, 503, 509, 523, 557, 563, 593, 599, 601, 617, 641, 653, 683, 691, 733, 743, 751, 757, 761, 773, 797, 823, 829, 857, 863, 937, 941, 971, 977, 1013, 1031, 1049

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Mar 24 2009

Keywords

• nonn

Crossrefs

Cf. A158708, A158709, A158710, A158711, A158712, A158713, A158714.

Programs

Mathematica

lst={};Do[p=Prime[n];If[ !PrimeQ[p1=Floor[p/2]+p]&&!PrimeQ[p2=Ceiling[p/2]+p],If[ !PrimeQ[p3=Floor[p1/2]+p1]&&!PrimeQ[p5=Ceiling[p1/2]+p1],If[ !PrimeQ[p4=Floor[p2/2]+p2]&&!PrimeQ[p6=Ceiling[p2/2]+p2],AppendTo[lst,Prime[n]]]]],{n,6!}];lst
nonpQ[p_]:=Module[{p1=Floor[p/2]+p,p2=Ceiling[p/2]+p},NoneTrue[ {p1,p2,Floor[ p1/2]+p1,Ceiling[p1/2]+p1,Floor[p2/2]+p2,Ceiling[p2/2]+ p2},PrimeQ]]; Select[Prime[Range[200]],nonpQ] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Nov 21 2019 *)