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A285983
Prime numbers p such that 3*p has distance <= 2 from the nearest twin prime number.
0
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
1,1
COMMENTS
Also prime numbers distance <= 1 from an element of A167379. - Danny Rorabaugh, May 04 2017
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
KEYWORD
nonn
AUTHOR
Dimitris Valianatos, Apr 29 2017
STATUS
approved