0,6
F(12) has 6 known factors with C1133 remaining. [Updated by Walter Nissen (nissen(AT)gtcinternet.com), Apr 02 2010]
F(13) has 4 known factors with C2391 remaining.
F(14) has one known factor with C4880 remaining. [Updated by Matt C. Anderson, Feb 14 2010]
W. Keller, Prime factors k.2^n + 1 of Fermat numbers F_m
W. Keller, Summary of factoring status for Fermat numbersF(n)
PSI (The algorithm company), Fermat factor status [Broken link?]
Eric Weisstein's World of Mathematics, Fermat Number
Cf. A000215.
Sequence in context: A029081 A168656 A005862 * A202276 A029115 A029101
Adjacent sequences: A046049 A046050 A046051 * A046053 A046054 A046055
nonn,hard
Eric Weisstein (eric(AT)weisstein.com)
Name corrected by Arkadiusz Wesolowski, Oct 31 2011
