%I #21 May 22 2018 11:30:20

%S 8,10,14,16,20,26,34,40,44,50,56,64,70,76,86,100,104,106,110,134,154,

%T 160,170,176,194,196,226,230,236,254,260,266,274,280,310,314,334,350,

%U 356,370,376,386,436,446,460,464,506,544,560,566,574,590,596

%N Numbers n such that n + 3 and n - 3 are both prime.

%C A010051(a(n)-3) * A010051(a(n)+3) = 1. - _Reinhard Zumkeller_, Nov 17 2015

%H Reinhard Zumkeller, <a href="/A087695/b087695.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A046117(n) - 3.

%p ZL:=[]:for p from 1 to 600 do if (isprime(p) and isprime(p+6) ) then ZL:=[op(ZL),(p+(p+6))/2]; fi; od; print(ZL); # _Zerinvary Lajos_, Mar 07 2007

%t lst={};Do[If[PrimeQ[n-3]&&PrimeQ[n+3], AppendTo[lst, n]], {n, 10^3}];lst (* _Vladimir Joseph Stephan Orlovsky_, Sep 08 2008 *)

%t Select[Range[600],AllTrue[#+{3,-3},PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, May 06 2015 *)

%o (Haskell)

%o a087695 n = a087695_list !! (n-1)

%o a087695_list = filter

%o (\x -> a010051' (x - 3) == 1 && a010051' (x + 3) == 1) [2, 4 ..]

%o -- _Reinhard Zumkeller_, Nov 17 2015

%o (PARI) p=2; q=3; forprime(r=5,1e3, if(q-p<7 && (q-p==6 || r-p==6), print1(p+3", ")); p=q; q=r) \\ _Charles R Greathouse IV_, May 22 2018

%Y Cf. A014574, A087678-A087683, A087696, A087697, A088763, A046117, A010051.

%K easy,nonn

%O 1,1

%A _Zak Seidov_, Sep 27 2003