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A152293 Primes of the form : (p-n)/(n+1)=prime and (n+1)*p+n=prime. n=3. 4

%I #2 Mar 31 2012 12:38:17

%S 11,31,47,151,271,359,439,599,719,1031,1759,1871,2287,2711,2767,2879,

%T 3719,3911,4079,5119,5527,5791,6199,6271,6991,7151,7607,7727,8447,

%U 8647,8831,9151,9391,9511,9839,10159,10687,10847,11279,12479,12919,13487

%N Primes of the form : (p-n)/(n+1)=prime and (n+1)*p+n=prime. n=3.

%C This is the general form : (p-n)/(n+1)=primeand(n+1)*p+n=prime; 'Safe' primes and'Sophie Germain' primes just one part of this general form; If n=1 then we got'Safe' primes and'Sophie Germain' primes.

%t lst={};n=3;Do[p=Prime[k];If[PrimeQ[(p-n)/(n+1)]&&PrimeQ[(n+1)*p+n],AppendTo[lst,p]],{k,7!}];lst

%Y Cf. A059455, A152292

%K nonn

%O 1,1

%A _Vladimir Joseph Stephan Orlovsky_, Dec 02 2008

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Last modified March 28 05:02 EDT 2024. Contains 371235 sequences. (Running on oeis4.)