A087681 Numbers n such that n + 6 and n - 6 are both prime.

11, 13, 17, 23, 25, 35, 37, 47, 53, 65, 67, 73, 77, 95, 103, 107, 133, 143, 145, 157, 173, 185, 187, 205, 217, 233, 235, 245, 257, 263, 275, 277, 287, 343, 353, 373, 395, 403, 415, 425, 427, 437, 455, 473, 485, 493, 497, 515, 563, 593, 607, 613, 625, 637, 647

Offset: 1

Author

Zak Seidov, Sep 27 2003

Keywords

• easy
• nonn

Comments

Many terms are of the form 5 + n + n^2 or 5 + 2*n^2: A054794.

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A054794.

Cf. A014574, A087678-A087683, A087695-A087697, A088766.

Programs

Mathematica

f[n_]:=PrimeQ[n-6]&&PrimeQ[n+6]; lst={}; Do[If[f[n],AppendTo[lst,n]],{n,2,7!,1}]; lst (* Vladimir Joseph Stephan Orlovsky, Aug 12 2009 *)
Select[Range[2,700],AllTrue[#+{6,-6},PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Jan 26 2019 *)