Happy Birthday   Paul Erdös
Born: March 26, 1913 in Budapest, Hungary
Died:  September 20, 1996 in Warsaw, Poland

Paul Erdös (1913-1996) was one of the most prolific mathematicians of all time, having authored over 1500 articles. An Erdös number measures the shortest distance of a researcher from Erdös on a graph whose edges represent co-authorship.
Among his numerous honors was the Wolf Prize of 1983-84.

Babe Ruth stamp

Aaron Hall of Fame plaque
Paul Erdos