Some sequences and number triangles which are related to Narayana polynomials and to q-Narayana polynomials for q=-1

Abstract

As is well known the Catalan numbers can be interpreted as numbers of Dyck paths. The Narayana polynomials and the q-Narayana polynomials for q=-1 can analogously be interpreted as certain weights of these paths. In the present note we try to get some information about the corresponding weights of bounded Dyck paths. This also leads to some number sequences and analogues of Pascals triangle which previously have occurred in other contexts. We consider some examples and obtain some results and conjectures.