%I A057468
%S A057468 2,3,5,17,29,31,53,59,101,277,647,1061,2381,2833,3613,3853,3929,5297,
%T A057468 7417,90217,122219,173191,256199,336353,485977,591827
%N A057468 Numbers n such that 3^n - 2^n is prime.
%C A057468 Some of the larger entries may only correspond to probable primes.
%C A057468 The 1137- and 1352-digit values associated with the terms 2381 and 2833 
               have been certified prime with Primo. - Rick L. Shepherd (rshepherd2(AT)hotmail.com), 
               Nov 12 2002
%C A057468 Or, numbers n such that A001047(n) is prime. - Zak Seidov (zakseidov(AT)yahoo.com), 
               Sep 17 2006
%C A057468 3 more terms found by Mike Oakes during 2003 - 2005: a(21) = 122219, 
               a(22) = 173191, a(23) = 256199. Corresponding numbers of decimal 
               digits are 58314, 82634, 122238. - Alexander Adamchuk (alex(AT)kolmogorov.com), 
               Dec 02 2006
%C A057468 All the terms found so far are prime. [From Dmitry Kamenetsky (dkamen(AT)rsise.anu.edu.au), 
               Dec 18 2008]
%D A057468 Mike Oakes (Mikeoakes2(AT)aol.com), personal communication, Feb 23, 2001, 
               found 90217.
%H A057468 Henri & Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/
               searchform.php?form=3%5En-2%5En&action=Search">PRP Records</a>.
%t A057468 Select[Range[10^3],PrimeQ[3^#-2^# ]&] - Vladimir Orlovsky (4vladimir(AT)gmail.com), 
               Apr 29 2008
%Y A057468 Cf. A058765, A000043 (Mersenne primes), A001047 (3^n-2^n).
%Y A057468 Sequence in context: A077499 A127061 A065725 this_sequence A127062 A029972 
               A077498
%Y A057468 Adjacent sequences: A057465 A057466 A057467 this_sequence A057469 A057470 
               A057471
%K A057468 nonn,hard,nice
%O A057468 1,1
%A A057468 Robert G. Wilson v (rgwv(AT)rgwv.com), Sep 09 2000
%E A057468 a(24) = 336353 found by Mike Oakes, Oct 15 2007. It corresponds to a 
               probable prime with 160482 decimal digits. - Alexander Adamchuk (alex(AT)kolmogorov.com), 
               Dec 25 2007
%E A057468 a[25] = 591827 found by Mike Oakes, Aug 25 2009; it corresponds to a 
               probable prime with 282374 digits. Mike Oakes (mikeoakes2(AT)aol.com), 
               Aug 31 2009
%E A057468 a[26] = 591827 found by Mike Oakes, Aug 25 2009; it corresponds to a 
               probable prime with 282374 digits. a[25] = 485977 found by Mike Oakes, 
               Sep 6 2009; it corresponds to a probable prime with 231870 digits. 
               Mike Oakes (mikeoakes2(AT)aol.com), Sep 08 2009