| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4648682 | Discrete Mathematics | 2011 | 5 Pages |
Abstract
We introduce the notion of ratio monotonicity for polynomials with nonnegative coefficients, and we show that, for n≥6n≥6, the qq-derangement numbers Dn(q)Dn(q) are strictly ratio monotone except for the last term when nn is even. This property implies the spiral property and log-concavity.
Keywords
Related Topics
Physical Sciences and Engineering
Mathematics
Discrete Mathematics and Combinatorics
Authors
William Y.C. Chen, Ernest X.W. Xia,