Paul Erdos was born in Budapest, Hungary on March 26, 1913. His two sisters died right before he was born, so his parents were extra cautious. At age 3, he was multiplying 3- digit numbers in his head and at age 4 he learned about negative numbers- he told his mother that 100-250= -150. Erdos was very eccentric- he never had a checkbook, a credit card; he never learned how to drive, and he never had health insurance. He traveled with a shabby suitcase and wearing a shabby suit and sandals. He supposedly remained celibate throughout his entire life. There were many restrictions on Jewish people entering universities in Hungary, but the Jewish Erdos won a national examination and so was allowed to enter in 1930. He got his doctorate in 1934, but was forced to leave Hungary not long after because he was Jewish. He went to Great Britain and also spent time in the United States.
With the rise of anti-communist feelings in the U.S. in the 1950's, he was asked to leave the country, but he was granted a visa in 1963. One thing that Erdos did that was very strange was to add initials to his name. By the time he was 74 years old, he had added 12 initials (P.G.O.M.L.D.A.D.L.D.C.D- Poor Great Old Man-Living Dead-Archeological Discovery-Legally Dead-Counts Dead).
Over 1500 papers were published by Erdos during his lifetime. Erdos himself has an Erdos number of 0. Anyone who wrote a paper with him has an Erdos number of 1. Someone who wrote a paper with someone who wrote a paper with Erdos has an Erdos number of 2, and so on. If there is no connection with a person to Erdos, then that person's Erdos number is infinite.
Erdos found an elementary...