  Counting substrings/subsequences that preserve some property (e.g.,
palindromes, squares) is an important mathematical interest in stringology.
Recently, Glen et al. studied the number of Lyndon factors in a string. A
string $w = uv$ is called a Lyndon word if it is the lexicographically smallest
among all of its conjugates $vu$. In this paper, we consider a more general
problem "counting Lyndon subsequences". We show (1) the maximum total number of
Lyndon subsequences in a string, (2) the expected total number of Lyndon
subsequences in a string, (3) the expected number of distinct Lyndon
subsequences in a string.
