3 papers
math.CO2026
A Grammatical Calculus for the Ramanujan Polynomials
William Y. C. Chen, Amy M. Fu, Elena L. Wang
The Ramanujan polynomials arise in three intertwined contexts. As remarked by BerndtEvans-Wilson, no combinatorial perspective seems to be alluded to in the original definition of…
math.CO2025
Enriched Cycle Structures and Roots of Permutations
William Y. C. Chen, Elena L. Wang
This paper is concerned with a duality between -regular permutations and -cycle permutations, and a monotone property due to Bóna-McLennan-White on the probability …
math.CO2025
On Ward Numbers and Increasing Schröder Trees
Elena L. Wang, Guoce Xin
The Ward numbers combinatorially enumerate set partitions with block sizes and phylogenetic trees (total partition trees). We prove that also counts \emp…