login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

Prime numbers p such that 3*p has distance <= 2 from the nearest twin prime number.
0

%I #12 May 12 2017 13:39:58

%S 2,3,5,7,11,13,19,23,37,47,59,61,67,79,89,103,139,173,191,199,269,271,

%T 277,293,349,353,383,409,431,433,439,541,557,643,677,709,757,769,863,

%U 887,911,929,991,1039,1087,1109,1123,1129,1153,1181,1187

%N Prime numbers p such that 3*p has distance <= 2 from the nearest twin prime number.

%C Also prime numbers distance <= 1 from an element of A167379. - _Danny Rorabaugh_, May 04 2017

%t fQ[n_] := (PrimeQ[3n -4] && PrimeQ[3n -2]) || (PrimeQ[3n +2] && PrimeQ[3n +4]); Join[{2}, Select[ Prime@ Range@ 200, fQ]] (* _Robert G. Wilson v_, Apr 30 2017 *)

%o (PARI) {

%o print1(2", ");

%o forprime(n=3,1000,

%o p3=3*n;

%o if((isprime(p3+2)&&isprime(p3+4))||(isprime(p3-2)&&isprime(p3-4)),

%o print1(n", ")

%o )

%o )

%o }

%Y Cf. A001359, A006512, A060212.

%K nonn

%O 1,1

%A _Dimitris Valianatos_, Apr 29 2017