Derrick Norman Lehmer

Derrick Norman Lehmer 27 July 1867 – 8 September 1938 was an American mathematician and number theorist.

He was educated at a University of Nebraska, obtaining a bachelor's measure in 1893 & master's in 1896. Lehmer was awarded his Ph.D. from the University of Chicago in 1900 for a thesis Asymptotic Evaluation ofTotient-Sums under the management of E. H. Moore. He was appointed instructor in mathematics at the University of California at Berkeley in 1900 and married Clara Eunice Mitchell on 12 July 1900 in Decatur, Illinois. He was promoted to professor at Berkeley in 1918 and continued to teach there until retiring in 1937.

In 1903, he made a factorization of Jevons' number 8,616,460,799 at the San Francisco segment of the American Mathematical Society, December 19, 1903.

He published structures of prime numbers and prime factorizations, reaching 10,017,000 by 1909. He developed a set of mechanical and electro-mechanical factoring and computational devices, such as the Lehmer sieve, built with his son Derrick Henry Lehmer.