libmath-combinatorics-perl 0.09-5.1 (amd64 binary) in ubuntu hirsute

 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
 .
 Math::Combinatorics provides a pure-perl implementation of nCk, nPk, and n!
 (combination, permutation, and factorial, respectively).