2017 Guts #17: Maximal number of subsequences
Source:
February 21, 2017
combinatorics
Problem Statement
Sean is a biologist, and is looking at a strng of length composed of the letters , , , . A substring of a string is a contiguous sequence of letters in the string. For example, the string has substrings: , , , , , , , , , . What is the maximum number of distinct substrings of the string Sean is looking at?