Comments on: Kimmo Eriksson and Svante Linusson,
The size of Fulton's essential set
April 7, 1995
The generating function on page 14 of the paper is well known.
See, e.g., generatingfunctionology, by H. Wilf, eq. 2.5.15 of
the 2nd edition. - Robin Chapman (rjc@maths.exeter.ac.uk)