He said: "You must be Don Sondergeld." 18 .   MATHEMATICIANS and Others    (see http://aleph0.clarku.edu/~djoyce/mathhist/chronology.html )     Pythagoras of Samos (c. 570-c. 495 BC): ( Greek )  He was an Ionian Greek philosopher , mathematician , and founder of the religious movement called Pythagoreanism . Most of the information about Pythagoras