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Primes p(n) such that gcd(p(n)-1, p(n+1)-1) > gcd(p(n)+1, p(n+1)+1).
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%I #15 Aug 02 2019 21:57:36

%S 13,31,37,61,73,89,97,109,113,151,157,181,193,199,211,229,241,271,277,

%T 313,331,349,367,373,389,397,401,421,433,449,457,523,541,571,601,607,

%U 613,619,631,661,673,691,701,727,733,751,757,761,769,811,853,877,929

%N Primes p(n) such that gcd(p(n)-1, p(n+1)-1) > gcd(p(n)+1, p(n+1)+1).

%C Sequence does not contain any lesser of twin primes A001359. (Proof. If p(n+1) = p(n)+2, then gcd(p(n)-1, p(n+1)-1) = 2 = gcd(p(n)+1, p(n+1)+1), so p(n) is not a term.) - _Jonathan Sondow_, Feb 03 2012

%H Harvey P. Dale, <a href="/A176181/b176181.txt">Table of n, a(n) for n = 1..1000</a>

%t lst={}; Do[p0=Prime[n]; p1=Prime[n+1]; If[GCD[p0-1,p1-1] > GCD[p0+1,p1+1], AppendTo[lst,p0]], {n,200}]; lst

%t Transpose[Select[Partition[Prime[Range[200]],2,1],GCD@@(#-1)>GCD@@(#+1)&]] [[1]] (* _Harvey P. Dale_, Sep 30 2014 *)

%Y Cf. A063091, A176180.

%K nonn

%O 1,1

%A _Vladimir Joseph Stephan Orlovsky_, Apr 11 2010

%E Definition clarified by _Jonathan Sondow_, Feb 03 2012