research

Explicit expression for the generating function counting Gessel's walks

Abstract

Gessel's walks are the planar walks that move within the positive quadrant Z+2\mathbb{Z}_{+}^{2} by unit steps in any of the following directions: West, North-East, East and South-West. In this paper, we find an explicit expression for the trivariate generating function counting the Gessel's walks with k0k\geq 0 steps, which start at (0,0)(0,0) and end at a given point (i,j)Z+2(i,j) \in \mathbb{Z}^2_+.Comment: 23 page

    Similar works