Ternary string
Source: Canada Repêchage 2015/7
June 18, 2016
combinatorics
Problem Statement
A -string is an infinite ternary string such that:[*] If there is a in position then there is a in position ,[*] if there is a in position then there is a in position ,[*] if there is a in position then there is a in position .For how many ordered triples of positive integers with does there exist -string?