Let S be a finite set and u a permutation on S. The permutation u\* on the set of 2-subsets of S is naturally induced by u. Suppose G is a graph and V(G), β¬(G) are the vertex set, the edge set, respectively. Let V(G) = S. If β¬(G) and u\*(β¬(G)), the image of β¬(G) by u\*, have no common element, then
On the Number of Permutations Avoiding a Given Pattern
β Scribed by Noga Alon; Ehud Friedgut
- Publisher
- Elsevier Science
- Year
- 2000
- Tongue
- English
- Weight
- 118 KB
- Volume
- 89
- Category
- Article
- ISSN
- 0097-3165
No coin nor oath required. For personal study only.
β¦ Synopsis
Let _ # S k and { # S n be permutations. We say { contains _ if there exist
Stanley and Wilf conjectured that for any _ # S k there exists a constant c=c(_) such that F(n, _) c n for all n. Here we prove the following weaker statement: For every fixed _ # S k , F(n, _) c n#* (n) , where c=c(_) and #*(n) is an extremely slow growing function, related to the Ackermann hierarchy.
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