Department of Mathematics - Stony Brook University
Yáng Huī (楊輝), ca. 1238–1298), Public domain, via Wikimedia Commons
Ishango bone, possibly about 25000 years old
The school of Athens Raphael, Public domain, via Wikimedia Commons
Melencolia I, 1514, Albrecht Dürer -Metropolitan Museum of Art- Public Domaint
The School of Athens: a key to the figures in the composition. Engraving by G. Volpato, after Raphael.via Wikimedia Commons