-
The Riordan group and symmetric lattice paths
- DENG Li-hua, DENG Yu-ping, Louis W. Shapiro
-
JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2015, 50(04):
82-89.
doi:10.6040/j.issn.1671-9352.0.2014.196
-
Abstract
(
1436 )
PDF (1159KB)
(
1108
)
Save
-
References |
Related Articles |
Metrics
The symmetric lattice paths are studied. Let dn, mn, and sn denote the number of symmetric Dyck paths, symmetric Motzkin paths, and symmetric Schröder paths of length 2n, respectively. By using Riordan group methods, six identities relating dn, mn, and sn are obtained and also two of them combinatorial proofs are given. Finally, some relations satisfied by the generic element of some special Riordan arrays are investigated and the average mid-height and the average number of points on the x-axis of symmetric Dyck paths of length 2n are obtained.