5 citations · 18 across the 17 of their papers we have counts for
27 papers
Commuting Eulerian operators
Shi-Mei Ma, Hao Qi, Jean Yeh +1
Motivated by the work of Visontai and Dey-Sivasubramanian on the gamma-positivity of some polynomials, we find the commutative property of a pair of Eulerian operators. As an appli…
Stirling permutation codes
Shi-Mei Ma, Hao Qi, Jean Yeh +1
The development of the theories of the second-order Eulerian polynomials began with the works of Buckholtz and Carlitz in their studies of an asymptotic expansion. Gessel-Stanley i…
Alternating runs of permutations and the central factorial numbers
Qi Fang, Ya-Nan Feng, Shi-Mei Ma
Let R(n,k) be the number of permutations of with k alternating runs. In this paper, we establish the relationships between R(n,k) and the central factorial numbe…
Positivity of Narayana polynomials and Eulerian polynomials
Shi-Mei Ma, Hao Qi, Jean Yeh +1
Gamma-positivity appears frequently in finite geometries, combinatorics and number theory. Motivated by the recent work of Sagan and Tirrell (Adv. Math., 374 (2020), 107387), we st…
Excedance-type polynomials and gamma-positivity
Shi-Mei Ma, Jun Ma, Jean Yeh +1
The object of this paper is to give a systematic treatment of excedance-type polynomials. We first give a sufficient condition for a sequence of polynomials to have alternatingly i…
Alternating Eulerian polynomials and left peak polynomials
Shi-Mei Ma, Qi Fang, Toufik Mansour +1
In this paper we present grammatical interpretations of the alternating Eulerian polynomials of types A and B. As applications, we derive several properties of the type B alternati…