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arXiv 1304.4286math.CO
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排列和词中的(a,b)-矩形模式

(a,b)-rectangle patterns in permutations and words

Sergey Kitaev, Jeffrey Remmel

摘要:

在本文中,我们引入了置换上的$(a,b)$ -矩形模式的概念,它不仅推广了置换中连续元素(键)的概念,而且与Brändén和Claesson最近引入的网格模式有关.我们把$(k,k)$ -矩形模式称为$k$ -盒模式。为了提供一个枚举结果的最大出现次数的1盒模式,我们建立了一个枚举结果的模式,避免有符号的排列。此外,我们扩展的概念$(k,\ell)$ -矩形模式的单词和二进制矩阵,并提供分布的$(1,\ell)$ -矩形模式的单词;明确的公式给出了多达7个字母的字母表,其中$\ell \in \{1,2\}$,而获得分布较大的字母取决于我们提供的矩阵求逆。我们也提供了类似的结果分布债券的话。作为推论,我们的研究,我们证实了一个猜想的Mathar的数量“稳定的乐高墙”的宽度为7,以及证明三个apturtures由于哈丁和一个猜想由于巴克。我们还列举了两个序列发表的哈丁在线百科全书的序列。

英文摘要:

In this paper, we introduce the notion of a $(a,b)$-rectangle pattern on permutations that not only generalizes the notion of successive elements (bonds) in permutations, but is also related to mesh patterns introduced recently by Brändén and Claesson. We call the $(k,k)$-rectangle pattern the $k$-box pattern. To provide an enumeration result on the maximum number of occurrences of the 1-box pattern, we establish an enumerative result on pattern-avoiding signed permutations. Further, we extend the notion of $(k,\ell)$-rectangle patterns to words and binary matrices, and provide distribution of $(1,\ell)$-rectangle patterns on words; explicit formulas are given for up to 7 letter alphabets where $\ell \in \{1,2\}$, while obtaining distributions for larger alphabets depends on inverting a matrix we provide. We also provide similar results for the distribution of bonds over words. As a corollary to our studies we confirm a conjecture of Mathar on the number of "stable LEGO walls" of width 7 as well as prove three conjectures due to Hardin and a conjecture due to Barker. We also enumerate two sequences published by Hardin in the On-Line Encyclopedia of Integer Sequences.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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