Keywords: Calkin-Wilf tree.svg Calkin “Wilf tree drawn using an H tree layout This tree contains each positive rational number exactly once; it is rooted at 1/1 and the two children of a/b are a+b /b and a/ a+b own David Eppstein 2009-05-03 Calkin “Wilf tree and sequence Files by User David Eppstein from en wikipedia |