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 A161868 Primes p such that both p+2 and p-2 are products of 3 distinct primes. 0

%I

%S 1237,1493,1549,1597,2137,2753,2767,2917,3533,3617,4013,4253,4919,

%T 5557,5683,5693,5783,6151,6353,6367,6917,6967,6983,7057,7187,7537,

%U 7687,7703,7883,8101,8167,8243,8447,8699,8731,8963,9697,9739,9787,9833,9887,10151

%N Primes p such that both p+2 and p-2 are products of 3 distinct primes.

%e 1237-2=5*13*19. 1237+2=3*7*59. 1493-2=3*7*71. 1493+2=5*13*23.

%t fQ[n_]:=Last/@FactorInteger[n]=={1,1,1};q=2;lst={};Do[p=Prime[n];If[fQ[p-q]&&fQ[p+q], AppendTo[lst,p]],{n,7!}];lst

%Y Cf. A007304. [_R. J. Mathar_, Jun 23 2009]

%K nonn

%O 1,1

%A _Vladimir Joseph Stephan Orlovsky_, Jun 20 2009

%E Definition rephrased by _R. J. Mathar_, Jun 23 2009

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