Ascent and descent
Source: Indian IMOTC 2005 Day 3 problem 3
September 23, 2005
analytic geometrycombinatorics unsolvedcombinatorics
Problem Statement
A merida path of order is a lattice path in the first quadrant of - plane joining to using three kinds of steps , and , i.e. joins to etc... An ascent in a merida path is a maximal string of consecutive steps of the form . If denotes the number of merdia paths of order with exactly ascents, compute and .