Identities from Weighted Motzkin Paths
William Y. C. Chen, Sherry H.F. Yan, and Laura L.M. Yang
Abstract: Based on a weighted version of the bijection between Dyck paths and 2-Motzkin paths, we find combinatorial
interpretations of two identities related to the Narayana polynomials and the Catalan numbers. These
interpretations answer two problems posed recently by Coker.