In mathematics, the Lehmer mean of a tuple of positive real numbers, named after Derrick Henry Lehmer,P. S. Bullen.

The Lehmer random number generator (named after D. H. Lehmer), sometimes also referred to as the Park–Miller random number generator (after Stephen K. Park and Keith W. Miller), is a type of linear congruential generator that operates in multiplicative group of integers modulo n.

In mathematics and in particular in combinatorics, the Lehmer code is a particular way to encode each possible permutation of a sequence of n numbers.