... The decreasing binary tree of p = 263498175the electronic journal of combinatorics 9(2) (2003), #A1 10[40] D. Zeilberger, A proof of Julian West’s conjecture that the number of two-stack-sortable ... rest of T (p) recursively, by taking T (p)andT (p), where pand pare thesubstrings of p on the two sides of n, and affixing them to a and b.WethencallT (p)thedecreasing binary tree of ... of T(p) is a vertex labeled n, the largest entry of p.Ifa is the largest entry of p on the left of n,andb is the largest entry of p on the right of n, then the root will havetwo children, the...