David Callan

activity

20002022

most citedTwo Bijections for Dyck Path Parameters

19 citations · 98 across the 36 of their papers we have counts for

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math.CO2022

A Note on Generalized Narayana Numbers

David Callan

We give a simple proof that the the number of Dyck paths of semilength $n$ with $i$ returns to ground level and $j$ peaks is the generalized Narayana number $\frac{i}{n} \binom{n}{…

math.CO2022

An involution on set partitions

David Callan

We present an involution on set partitions that interchanges two statistics related to relative size of block entries and use it to establish an equidistribution on objects counted…

math.CO2022

A bijection for Delannoy paths

David Callan

We exhibit a bijection between central Delannoy $n$ -paths, that is, lattice paths from the origin to $(n, n)$ with steps $E = (1, 0), N = (0, 1), D = (1, 1)$ and the lattice paths from th…