As shown by Bousquet-Mélou–Claesson–Dukes–Kitaev (2010), ascent sequences can be
used to encode (2+ 2)-free posets. It is known that ascent sequences are enumerated by the …

A partial order≺ on [n] is naturally labelled (NL) if x≺ y implies x< y. We establish a bijection
between {3, 2+2}-free NL posets and 12–34-avoiding permutations, determine functional …

The Fishburn numbers can be defined as the coefficients of the generating function
Combinatorially, the Fishburn numbers enumerate certain supersets of sets enumerated by …

Ascent sequences were introduced by Bousquet-Mélou, Claesson, Dukes, and Kitaev in [1],
who showed that ascent sequences of length n are in 1-to-1 correspondence with (2+ 2)-free …

In this paper, we provide an asymptotic for the number of row-Fishburn matrices of size n
which settles a conjecture by Vit Jelínek. Additionally, using q-series constructions we …

Abstract Disanto, Ferrari, Pinzani and Rinaldi have introduced the concept of Catalan pair,
which is a pair of partial orders (S, R) satisfying certain axioms. They have shown that …

The combined work of Bousquet-Mélou, Claesson, Dukes, Jelínek, Kitaev, Kubitzke and
Parviainen has resulted in non-trivial bijections among ascent sequences,(2+ 2)-free posets …

We present (bi-) symmetric generating functions for the joint distributions of Euler–Stirling
statistics on permutations, including the number of descents (des), inverse descents (ides) …

Tree data appear naturally in many scientific domains. Their intrinsically non-Euclidean
nature and the combinatorial explosion phenomenon make their analysis delicate. In this …

A direct saddle-point analysis (without relying on any modular forms or functional equations)
is developed to establish the asymptotics of Fishburn matrices and a large number of other …