Pál Erdős, who died in 1996, remains one of the most published mathematicians in history — second only to Leonhard Euler by some counts — and was notorious for having no fixed address for most of his adult life, traveling between colleagues with a single suitcase and solving problems in exchange for cash prizes he rarely bothered to collect. Hungary has a long tradition of honoring its mathematical and scientific figures on commemorative coinage, and Erdős, despite spending decades effectively stateless after U.S. authorities revoked his re-entry visa in 1954 during McCarthyite security reviews, retained his Hungarian identity throughout.
Pál Erdős, who died in 1996, remains one of the most published mathematicians in history — second only to Leonhard Euler by some counts — and was notorious for having no fixed address for most of his adult life, traveling between colleagues with a single suitcase and solving problems in exchange for cash prizes he rarely bothered to collect. Hungary has a long tradition of honoring its mathematical and scientific figures on commemorative coinage, and Erdős, despite spending decades effectively stateless after U.S. authorities revoked his re-entry visa in 1954 during McCarthyite security reviews, retained his Hungarian identity throughout.