A285983 - OEIS

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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

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

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

LINKS

Table of n, a(n) for n=1..51.

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 *)

PROG

(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", ")

)

}

CROSSREFS

Cf. A001359, A006512, A060212.

Sequence in context: A130807 A338577 A030145 * A020588 A227202 A237827

Adjacent sequences: A285980 A285981 A285982 * A285984 A285985 A285986

KEYWORD

nonn

AUTHOR

Dimitris Valianatos, Apr 29 2017

STATUS

approved