B. Salvy et P. Zimmermann, GFUN - A MAPLE PACKAGE FOR THE MANIPULATION OF GENERATING AND HOLONOMIC FUNCTIONS IN ONE VARIABLE, ACM transactions on mathematical software, 20(2), 1994, pp. 163-177
We describe the GFUN package which contains functions for manipulating
sequences, linear recurrences, or differential equations and generati
ng functions of various types. This article is intended both as an ele
mentary introduction to the subject and as a reference manual for the
package.