A combinatorial proof of the logconcavity of the number of permutations with $k$ runs
Miklos Bona
University of Florida
February 11,
4:15pm
refreshments at 3:45pm
2338
ABSTRACT

We combinatorially prove that the number $R(n,k)$ of
permutations of length $n$ having $k$
runs is a logconcave sequence in $k$, for all $n$. Our proof involves
a simple and useful lattice path interpretation of permutations.
We also give a new combinatorial proof for the logconcavity of the Eulerian
numbers. This is joint work with Richard Ehrenborg.

Speaker's Contact Info: bona(atsign)math.ufl.edu
Return to seminar home page
Page loaded on January 12, 2000 at 04:02 PM.

Copyright © 199899, Sara C. Billey.
All rights reserved.

