A285983 Prime numbers p such that 3*p has distance <= 2 from the nearest twin prime number.

2, 3, 5, 7, 11, 13, 19, 23, 37, 47, 59, 61, 67, 79, 89, 103, 139, 173, 191, 199, 269, 271, 277, 293, 349, 353, 383, 409, 431, 433, 439, 541, 557, 643, 677, 709, 757, 769, 863, 887, 911, 929, 991, 1039, 1087, 1109, 1123, 1129, 1153, 1181, 1187

Offset: 1

Author

Dimitris Valianatos, Apr 29 2017

Keywords

• nonn

Comments

Also prime numbers distance <= 1 from an element of A167379. - Danny Rorabaugh, May 04 2017

Crossrefs

Cf. A001359, A006512, A060212.

Programs

Mathematica

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 *)

PARI

{
print1(2", ");
forprime(n=3,1000,
         p3=3*n;
         if((isprime(p3+2)&&isprime(p3+4))||(isprime(p3-2)&&isprime(p3-4)),
             print1(n", ")
           )
        )
}