2 citations · 5 across the 6 of their papers we have counts for
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Classical and vincular patterns of length three in generalized alternating permutations
Zhenhua Luo, Junting Wang, Ziyi Yang +2
Let k be an integer at least 2, and let D_{N,k} be the set of permutations of {1,...,N} whose descent set is exactly {k, 2k, ..., k*floor((N-1)/k)}. We enumerate the elements of D_…
A decomposition of ballot permutations, pattern avoidance and Gessel walks
Zhicong Lin, David G. L. Wang, Tongyuan Zhao
A permutation whose any prefix has no more descents than ascents is called a ballot permutation. In this paper, we present a decomposition of ballot permutations that enables us to…
Refined Eulerian numbers and ballot permutations
Tongyuan Zhao, Yue Sun, Feng Zhao
A ballot permutation is a permutation π such that in any prefix of π the descent number is not more than the ascent number. In this article, we obtained a formula in close form for…
The peak and descent statistics over ballot permutations
David G. L. Wang, T. Zhao
A ballot permutation is a permutation such that in any prefix of the descent number is not more than the ascent number. By using a reversal concatenation map, we give a for…
Convolution Preserves Partial Synchronicity of Log-concave Sequences
H. Hu, David G. L. Wang, F. Zhao +1
In a recent proof of the log-concavity of genus polynomials of some families of graphs, Gross et al. defined the weakly synchronicity relation between log-concave sequences, and co…
The Real-Rootedness and Log-concavities of Coordinator Polynomials of Weyl Group Lattices
David G. L. Wang, Tongyuan Zhao
It is well-known that the coordinator polynomials of the classical root lattice of type and those of type are real-rooted. They can be obtained, either by the Aissen-Sc…