The excedance set of a permutation π = π 1 π 2 • • • π n is the set of indices i for which π i > i. We give a formula for the number of permutations with a given excedance set and recursive formulas satisfied by these numbers. We prove log-concavity of certain sequences of these numbers and we show
Proof of a Conjecture of Ehrenborg and Steingrı́msson on Excedance Statistic
✍ Scribed by Yi Wang
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 95 KB
- Volume
- 23
- Category
- Article
- ISSN
- 0195-6698
No coin nor oath required. For personal study only.
✦ Synopsis
We give an affirmative answer to a conjecture of Ehrenborg and Steingrímsson on the general log-concavity of the excedance statistic.
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