4 papers
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…
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…
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 f…
The Wide Band Cayley Continuants
William Y. C. Chen, Elena L. Wang
The Cayley continuants are referred to the determinants of tridiagonal matrices in connection with the Sylvester continuants. Munarini-Torri found a striking combinatorial interpre…