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%I A093179
%S A093179 3,5,17,257,65537,641,274177,59649589127497217,1238926361552897,2424833,
%T A093179 45592577,319489,114689,2710954639361
%N A093179 Smallest factor of the n-th Fermat number F(n) = 2^(2^n)+1.
%H A093179 Ivars Peterson, <a href="http://www.sciencenews.org/articles/20030301/
               mathtrek.asp">Cracking Fermat Numbers</a>.
%H A093179 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               FermatNumber.html">Fermat Number</a>
%e A093179 F(0) = 2^(2^0)+ 1 = 3, prime.
%e A093179 F(5) = 2^(2^5)+ 1 = 4294967297 = 641*6700417.
%e A093179 So 3 as the 0-th entry and 641 is the 5-th term.
%o A093179 (PARI) g(n)=for(x=9,n,y=Vec(ifactor(2^(2^x)+1));print1(y[1]",")) - Cino 
               Hilliard (hillcino368(AT)hotmail.com), Jul 04 2007
%Y A093179 Cf. A000051, A070592.
%Y A093179 Leading entries in triangle A050922.
%Y A093179 Sequence in context: A019434 A164307 A125045 this_sequence A067387 A050922 
               A070592
%Y A093179 Adjacent sequences: A093176 A093177 A093178 this_sequence A093180 A093181 
               A093182
%K A093179 nonn,more,hard
%O A093179 0,1
%A A093179 Eric Weisstein (eric(AT)weisstein.com), Mar 27, 2004
%E A093179 Edited by N. J. A. Sloane (njas(AT)research.att.com), Jul 02 2008 at 
               the suggestion of R. J. Mathar

    
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Last modified December 20 16:54 EST 2009. Contains 171081 sequences.


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