5 papers
Bijective proofs of several conjectures on Jacobi permutations
Zhicong Lin, Yongzhou Wen, Sherry H. F. Yan
Jacobi permutations, invented by Viennot in the context of the Jacobi elliptic functions, are counted by the Euler numbers. Recently, Henke, Hoffman, Stephens, Yuan, and Zhuang stu…
A bijection between - and -avoiding permutations preserving -stack-sortability
Yang Li, Sergey Kitaev, Zhicong Lin +1
We construct a bijection between - and -avoiding permutations that preserves the property of -stack-sortability. Our bijection transforms natural statistics between th…
Bijections in weakly increasing trees via binary trees
Yang Li, Zhicong Lin
As a unification of increasing trees and plane trees, the weakly increasing trees labeled by a multiset was introduced by Lin-Ma-Ma-Zhou in 2021. Motived by some symmetries in plan…
Combinatorics on bi--positivity of -Eulerian polynomials
Sherry H. F. Yan, Xubo Yang, Zhicong Lin
The -Eulerian polynomials were introduced as ascent polynomials over -inversion sequences by Savage and Viswanathan. The bi--positivity of the -Eu…
Bijections around Springer numbers
Shaoshi Chen, Yang Li, Zhicong Lin +1
Arnol'd proved in 1992 that Springer numbers enumerate the Snakes, which are type analogs of alternating permutations. Chen, Fan and Jia in 2011 introduced the labeled ballot p…