A bijection for Delannoy paths

Abstract

We exhibit a bijection between central Delannoy $n$-paths, that is, lattice paths from the origin to $(n,n)$ with steps $E=(1,0),N=(0,1),D=(1,1)$ and the lattice paths from the origin to $(n+1,n)$ where the only restriction on the steps is that they have finite nonnegative slope.

4 pages, 2 figures