%I A046052
%S A046052 1,1,1,1,1,2,2,2,2,3,4,5
%N A046052 Number of factors of Fermat number F(n).
%H A046052 Wilfrid Keller, <a href="http://www.prothsearch.net/fermat.html">Prime 
               factors k.2^n + 1 of Fermat numbers F_m</a>
%H A046052 PSI (The algorithm company), <a href="http://www.perfsci.com/prizes.html">
               Fermat factor status</a>
%H A046052 W. Keller, <a href="http://www.prothsearch.net/fermat.html#Summary">Summary 
               of factoring status for Fermat numbersF(n)</a>
%H A046052 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               FermatNumber.html">Fermat Number</a>
%Y A046052 Cf. A000215.
%Y A046052 Sequence in context: A029102 A029081 A005862 this_sequence A029115 A029101 
               A029080
%Y A046052 Adjacent sequences: A046049 A046050 A046051 this_sequence A046053 A046054 
               A046055
%K A046052 nonn,hard
%O A046052 0,6
%A A046052 Eric Weisstein (eric(AT)weisstein.com)
%E A046052 F(12) has 5 known factors with C1187 remaining
%E A046052 F(13) has 4 known factors with C2391 remaining
%E A046052 F(14) has no known factors but is composite.