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%I #2 Mar 31 2012 12:38:28
%S 2,3,20759,103619,145109,148853,199109,291503,353459,356591,362759,
%T 367733,475523,521831,527123,552059,603191,609809,639839,691979,
%U 726419,810809,812939,825491,940421,980471,998213,1103561,1117793,1132811
%N Sophie Germain primes p surrounded by Sophie Germain primes.
%t PrimeNext[n_]:=Module[{k},k=n+1;While[ !PrimeQ[k],k++ ];k]; PrimePrev[n_]:=Module[{k},k=n-1;While[ !PrimeQ[k],k-- ];k]; f[n_]:=PrimeQ[2*n+1]; lst={};Do[p=Prime[n];If[f[p],If[f[PrimePrev[p]]&&f[PrimeNext[p]],AppendTo[lst,p]]],{n,9!}];lst
%Y Cf. A005384
%K nonn
%O 1,1
%A _Vladimir Joseph Stephan Orlovsky_, Dec 04 2009