Title of article :
Combinatorial parameters on bargraphs of permutations
Author/Authors :
Mansour ، Toufik - University of Tennessee , Shattuck ، Mark - University of Tennessee
Abstract :
In this paper, we consider statistics on permutations of length n represented geometrically as bargraphs having the same number of horizontal steps. More precisely, we find the joint distribution of the descent and up step statistics on the bargraph representations, thereby obtaining a new refined count of permutations of a given length. To do so, we consider the distribution of the parameters on permutations of a more general multiset of which Sn is a subset. In addition to finding an explicit formula for the joint distribution on this multiset, we provide counts for the total number of descents and up steps of all its members, supplying both algebraic and combinatorial proofs. Finally, we derive explicit expressions for the sign balance of these statistics, from which the comparable results on permutations follow as special cases.
Keywords :
combinatorial statistic , q , generalization , bargraph , permutations.
Journal title :
Transactions on Combinatorics
Journal title :
Transactions on Combinatorics