Derrick Norman Lehmer

Derrick Norman Lehmer at the piano

Derrick Norman Lehmer (born July 27, 1867 in Somerset (Indiana) , † September 8, 1938 in Berkeley (California) ) was an American mathematician who dealt with number theory .

Lehmer graduated from the University of Nebraska with a bachelor's degree in 1893 and was then a surveyor for the railroad. After continuing his studies, he received his master's degree in 1896, was at the Worthington Military Academy and then studied at the University of Chicago , where he received his doctorate in 1900 with Eliakim Hastings Moore ( Asymptotic Evaluation of Certain Totient-Sums ). In 1900 he became an instructor at the University of California, Berkeley , and married Clara Eunice Mitchell, with whom he had two sons, including the mathematician Derrick Henry Lehmer , and three daughters. In 1918 he became a professor at Berkeley and in 1937 he retired.

Among other things, Lehmer dealt with continued fractions and factoring algorithms. In 1909 he published a list of the smallest prime factors of the numbers not divisible by 2, 3, 5 or 7 up to around 10 million and in 1914 a list of the prime numbers up to around 10 million. In 1903 he presented the prime factors of the number 8,616,460,799, solving a challenge from William Stanley Jevons , who had doubted that this was within the range of the mathematical skills of the time.

In the 1920s, Lehmer worked on electromechanical calculating machines for factoring numbers that used punch cards (Lehmer sieve, factor stencils). He also worked with his son Derrick Henry Lehmer. The construction of the machine was funded by the Carnegie Institution in Washington and presented at the World's Fair in Chicago in the 1930s.

Lehmer also wrote poems, songs with compositions, two operas and an unpublished play about Edward Kelly and John Dee .

In 1932 he received an honorary doctorate from the University of Nebraska. He was a Fellow of the American Association for the Advancement of Science and a Vice President of the Mathematical Association of America .

Fonts

• Factor table for the first ten millions containing the smallest factor of every number not divisible by 2, 3, 5, or 7 between the limits 0 and 10017000, Carnegie Institution of Washington. Publication no.105, 1909.
• An Elementary Course in Synthetic Projective Geometry, Boston, Ginn and Company 1917, digitized , University of Michigan
• On a new method of factorization, Proc Natl Acad Sci US A., Vol. 11, 1925, pp. 97-98
• Factor Stencils, Carnegie Institution, Washington DC 1929
• On the enumeration of magic cubes, Bull. Amer. Math. Soc., Vol. 40, 1934, pp. 833-837

Web links

Commons : Derrick Norman Lehmer  - Collection of pictures, videos and audio files

• John J. O'Connor, Edmund F. Robertson :  Derrick Norman Lehmer. In: MacTutor History of Mathematics archive .
• Factor stencils by Lehmer in the National Museum of American History