Abstract
In this paper, we identify all members of the (4,4)-Wilf equivalence class for ascent sequences corresponding to the Catalan number Cn = 1/n+1(2n/n). This extends recent work concerning avoidance of a single pattern and pro-vides apparently new combinatorial interpretations for Cn. In several cases, the subset of the class consisting of those members having exactly m ascents is given by the Narayana number Nn,m+1 = 1/n(n/m+1)(n/m). We conclude by considering a further refinement in the case of avoiding 021.
Original language | English |
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Pages (from-to) | 288-303 |
Number of pages | 16 |
Journal | Applicable Analysis and Discrete Mathematics |
Volume | 8 |
Issue number | 2 |
DOIs | |
State | Published - 2014 |
Keywords
- Ascent sequence
- Catalan number
- Kernel method
- Narayana number
ASJC Scopus subject areas
- Analysis
- Discrete Mathematics and Combinatorics
- Applied Mathematics