Derrick Norman Lehmer

Derrick Norman Lehmer (1867 to 1938) was an American mathematician and number theorist. He studied at the University of Nebraska, taking a bachelor's degree in 1893 and a master's in 1896, and gained his PhD at the University of Chicago in 1900 with a thesis on the asymptotic evaluation of certain totient sums, supervised by E. H. Moore. The same year he became an instructor in mathematics at the University of California, Berkeley, where he was promoted to professor in 1918 and taught until his retirement in 1937. In 1903 he presented a factorization of Jevons's number, 8,616,460,799, to the San Francisco Section of the American Mathematical Society. He published tables of prime numbers and prime factorizations that reached 10,017,000 by 1909, and with his son Derrick Henry Lehmer he built mechanical and electro-mechanical factoring and computing devices, among them the Lehmer sieve. His papers also treated Hurwitzian continued fractions, Jacobi's extension of the continued fraction algorithm and the enumeration of magic cubes.