6 papers
Decreasing Runs in Quasi-Stirling Permutations of Multisets
Hanqian Fang
As a natural extension of Stirling permutations, quasi-Stirling permutations are multipermutations with the property that for any subsequence sat…
On the Summability Problem of Multivariate Rational Functions in the Mixed Case
Shaoshi Chen, Lixin Du, Hanqian Fang +1
Continuing previous work, this paper focuses on the summability problem of multivariate rational functions in the mixed case in which both shift and -shift operators can appear.…
On stable patterns and properties on permutations of multisets
Shaoshi Chen, Hanqian Fang, Sergey Kitaev
In this paper, we study properties and patterns on permutations of multisets whose multivariate generating functions are symmetric. We interpret this phenomenon through the lens of…
A zero-test for D-algebraic transseries
Shaoshi Chen, Hanqian Fang, Joris van der Hoeven
Consider formal power series that are defined as the solutions of a system of polynomial differential equations together with a sufficient numbe…
Analytic properties arising from the Baxter numbers
Hanqian Fang, Candice X. T. Zhang, James J. Y. Zhao
Baxter numbers are known as the enumeration of Baxter permutations and numerous other discrete structures, playing a significant role across combinatorics, algebra, and analysis. I…
Symbolic Summation of Multivariate Rational Functions
Shaoshi Chen, Lixin Du, Hanqian Fang
Symbolic summation as an active research topic of symbolic computation provides efficient algorithmic tools for evaluating and simplifying different types of sums arising from math…