Combinatorics is the branch of mathematics studying the enumeration, combination, and permutation of sets of elements and the mathematical relations that characterize their properties. As a jumping off point, refer to: http://mathworld.wolfram.com/Combinatorics.html This module provides a pure-perl implementation of nCk, nPk, and n! (combination, permutation, and factorial, respectively). WWW: https://metacpan.org/release/Math-Combinatorics