摘要
Making use of a combinatorial approach, we prove two refined major-balance identities on the 321-avoiding involutions in Sn, respecting the number of fixed points and the number of descents, respectively. The former one is proved in terms of ordered trees whose non-root nodes have exactly two children, and the latter one is proved in terms of lattice paths within a ⌊n2⌋×⌈n2⌉ rectangle.
原文 | 英語 |
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頁(從 - 到) | 250-264 |
頁數 | 15 |
期刊 | European Journal of Combinatorics |
卷 | 49 |
DOIs | |
出版狀態 | 已發佈 - 2015 10月 1 |
ASJC Scopus subject areas
- 離散數學和組合