### v15i1r52 — Comment by the editors.

The paper was accepted Mar 25, 2008 not
Mar 25, 2007 as stated in the paper.

### v15i1r52 — Comment by Christian Krattenthaler, May 12, 2008.

Formula (2) is equivalent to Formula (11) in Ref. [3], as is
seen by replacing α by -βn-α+n-1 in the latter
formula.

In the same way, Formula (3) is equivalent to the second main
result in "Some convolutions with multinomial coefficients and
related probability distributions" by S. G. Mohanty (SIAM Review 8
(1966), 501-509).

These convolution type formulas are given coverage also in
Mohanty's book "Lattice Path Counting and Applications"
(Academic Press, 1979) in Chapter 6, Section 2. It is also
briefly hinted at how these convolution formulas follow
rather easily by decomposition of paths (see Chapter 4, page 89).