# Édouard Lucas

**François Édouard Anatole Lucas** (∗ 4. April 1842; † 3. October 1891) was born in Amiens, France and educated at the Ecole Normale Superieure. He worked as a mathematician at the Paris Observatory, served for a time in the army during the Franco-Prussian War, and then became a professor of mathematics in Paris, first at the Lycée Saint Louis and later at Lycée Charlemagne.

Lucas is known for his study of the Fibonacci numbers, including a formula for finding the nth term of the sequence. The related Lucas sequence is named after him. He devised a new method for testing the primality of numbers that did not require finding all of their factors. In 1930, Derrick Henry Lehmer expanded on this work to create the Lucas-Lehmer test. In 1876, Lucas proved the primality of [math]2^{127}{-}1[/math] (M12) and this remained the highest Mersenne prime for almost 75 years, and is still the highest prime number discovered without the aid of a computer.

Lucas was also interested in recreational mathematics, inventing the Tower of Hanoi puzzle, which is now well known through many variants. His four-volume *Recreations Mathematiques* published between 1882 and 1894 has become a classic in its field.

He died under unusual circumstances. At a dinner for the French Academy for the Advancement of Science, a waiter dropped some plates and a piece of broken china scratched Lucas' cheek. He died a few days later of septicemia (some authorities say erysipelas, a type of bacterial infection).