  Consider an $m\times n$ table $T$ and latices paths $\nu_1,\ldots,\nu_k$ in
$T$ such that each step $\nu_{i+1}-\nu_i=(1,1)$, $(1,0)$ or $(1,-1)$. The
number of paths from the $(1,i)$-blank (resp. first column) to the
$(s,t)$-blank is denoted by $\mathcal{D}^i(s,t)$ (resp. $\mathcal{D}(s,t)$).
Also, the number of all paths form the first column to the las column is
denoted by $\mathcal{I}_m(n)$. We give explicit formulas for the numbers
$\mathcal{D}^1(s,t)$ and $\mathcal{D}(s,t)$.
