Erratum to "A lattice walk approach to the q-counting of multiset permutations" by D. Zeilberger

in the atricle A lattice walk approach to the q-counting of multiset permutations by D. Zeilberger, on p.198 the bottm formula, inside the sigma there is a missing p^{(n-k)(n-k-1)/2} that should multiply the summand.