activity
20232026
collaborators

9 papers

math.CO2026

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

Johann Cigler

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…

math.CO2026

Continued fractions related to Narayana polynomials

Johann Cigler

The generating functions of some sequences of Catalan numbers and Narayana polynomials have simple expansions as continued fractions of Jacobi type. We give an overview of these fa…

math.CO2026

Symmetric Dyck paths and q-Narayana numbers

Johann Cigler

We show that the q-Narayana numbers for q=-1 count symmetric Dyck paths according to the number of their valleys.

math.CA2025

Nice q-analogs of orthogonal polynomials with nice moments: Some simple examples

Johann Cigler

In this note I collect some typical examples of orthogonal polynomials with simple moments where both moments and orthogonal polynomials have nice q-analogs.

math.NT2024

Some elementary remarks on the powers of a partial theta function and corresponding q-analogs of the binomial coefficients

Johann Cigler

We obtain formulas for the coefficients of positive and negative powers of a partial theta function.

math.CO2024

Hankel determinants of backward shifts of the coefficients of a partial theta function

Johann Cigler

We study some polynomials which are related to Hankel determinants of backward shifts of the coefficients of a partial theta function. In this version an appendix is added which gi…

math.CO2024

Some remarks about Hankel determinants which are related to Catalan-like numbers

Johann Cigler

This note presents some results about Hankel determinants of backwards shifted Catalan-like numbers and related sequences.

math.CO2024

Hankel determinants of convolution powers of Catalan numbers revisited

Johann Cigler

Using a slightly generalized result of George Andrews and Jet Wimp this note gives a simple computational proof of some Hankel determinants of backwards shifts of convolution power…

math.CO2023

Some results and conjectures about Hankel determinants of sequences which are related to Catalan-like numbers

Johann Cigler

Martin Aigner introduced Catalan-like numbers as elements of the first column of admissible matrices and studied Hankel determinants of their forward shifts. In this paper we colle…