C. Krattenthaler et M. Prohaska, A remarkable formula for counting nonintersecting lattice paths in a ladder with respect to turns, T AM MATH S, 351(3), 1999, pp. 1015-1042
We prove a formula, conjectured by Conca and Herzog, for the number of all
families of nonintersecting lattice paths with certain starting and end poi
nts in a region that is bounded by an upper ladder. Thus we are able to com
pute explicitly the Hilbert series for certain one-sided ladder determinant
al rings.