تقرير
Enumerating 1324-avoiders with few inversions
| العنوان: | Enumerating 1324-avoiders with few inversions |
|---|---|
| المؤلفون: | Linusson, Svante, Verkama, Emil |
| سنة النشر: | 2024 |
| المجموعة: | Mathematics |
| مصطلحات موضوعية: | Mathematics - Combinatorics, 05A05, 05A15 |
| الوصف: | We enumerate the numbers $Av_n^k(1324)$ of 1324-avoiding $n$-permutations with exactly $k$ inversions for all $k$ and $n \geq (k+7)/2$. The result depends on a structural characterization of such permutations in terms of a new notion of almost-decomposability. In particular, our enumeration verifies half of a conjecture of Claesson, Jel\'inek and Steingr\'imsson, according to which $Av_n^k(1324) \leq Av_{n+1}^k(1324)$ for all $n$ and $k$. Proving also the other half would improve the best known upper bound for the exponential growth rate of the number of $1324$-avoiders from $13.5$ to approximately $13.002$. Comment: 23 pages |
| نوع الوثيقة: | Working Paper |
| URL الوصول: | http://arxiv.org/abs/2408.15075 |
| رقم الأكسشن: | edsarx.2408.15075 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |