A189051 Numbers n such that n+/-2 and n^2+/-2 are all primes.

9, 15, 21, 309, 441, 1611, 2955, 3081, 3879, 5529, 7209, 7755, 7875, 13761, 15015, 15729, 16659, 21561, 22155, 35595, 37059, 38199, 45291, 50049, 51429, 59619, 63855, 67215, 67941, 71331, 72891, 83061, 96459, 96909, 102795, 106959, 111495

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Formula

Intersection of A087679 and A108701.

Maple

select(n -> isprime(n-2) and isprime(n+2) and isprime(n^2-2) and isprime(n^2+2),
[seq(i, i=3..10^6, 6)]); # Robert Israel, Jun 23 2017

Mathematica

pQ[n_]:=Module[{n2=n^2}, And@@PrimeQ[{n+2, n-2, n2+2, n2-2}]]; Select[Range[ 120000], pQ] (* Harvey P. Dale, Jun 04 2011 *)

Prog

(PARI) forstep(n=3, 100000, 6, if(isprime(n-2)&isprime(n+2)&isprime(n^2-2)&isprime(n^2+2), print1(n", ")))
(Magma) [n: n in [1..2000000]|IsPrime(n-2)and IsPrime(n+2)and IsPrime(n^2-2)and IsPrime(n^2+2)]; // Vincenzo Librandi, Apr 20 2011

Crossrefs

Cf. A087679, A108701.

Sequence in context: A125215 A102739 A124622 * A374933 A274288 A172292

Adjacent sequences: A189048 A189049 A189050 * A189052 A189053 A189054

Keyword

nonn

Author

Juri-Stepan Gerasimov, Apr 16 2011

Extensions

Corrected and extended by Franklin T. Adams-Watters, Apr 16 2011

Status

approved