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%I A066388
%S A066388 6,30,660,810,2130,2550,3330,3390,5850,6270,10530,33180,41610,44130,
%T A066388 53550,55440,57330,63840,65100,70380,70980,72270,74100,74760,78780,
%U A066388 80670,81930,87540,93240,102300,115470,124770,133980,136950,156420
%N A066388 Numbers n such that n and 2n are both between a pair of twin primes.
%C A066388 Also terms of A014574 such that twice the term is also in A014574. Related 
               to a problem of anti-divisors.
%C A066388 A117499(a(n)) = 4. - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), 
               Mar 23 2006
%H A066388 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               BitwinChain.html">Bitwin Chain</a>
%e A066388 For n=30, 29 and 31 are prime, as are 59 and 61.
%t A066388 lst={}; Do[p1=Prime[n]; p2=Prime[n+1]; d=2; If[p2-p1==d, w=p1+1; If[PrimeQ[2*w-1]&&PrimeQ[2*w+1], 
               AppendTo[lst, w]]], {n, 1, 10^4}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), 
               Aug 07 2008]
%Y A066388 Cf. A001359, A006512, A012574.
%Y A066388 Sequence in context: A119634 A075591 A130075 this_sequence A088256 A136349 
               A119411
%Y A066388 Adjacent sequences: A066385 A066386 A066387 this_sequence A066389 A066390 
               A066391
%K A066388 nonn
%O A066388 1,1
%A A066388 Jud McCranie (j.mccranie(AT)comcast.net), Dec 23 2001

    
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Last modified November 29 12:46 EST 2009. Contains 167659 sequences.


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