Seems like noone mentions this big news (IMHO) yet. So here I go! On February 3, 2010, Tapio Rajala reported at http://mersenneforum.org/showthread.php?t=13051 that he found a prime factor of the Fermat number F14 with GIMPS' ECM. Until then, F14 = 2^2^14 + 1 had been the smallest composite Fermat number with no known prime factors. Warut