English

Continued fractions, statistics, and generalized patterns

Combinatorics 2007-05-23 v2

Abstract

Recently, Babson and Steingrimsson (see \cite{BS}) introduced generalized permutations patterns that allow the requirement that two adjacent letters in a pattern must be adjacent in the permutation. Following \cite{BCS}, let ekπe_k\pi (respectively; fkπf_k\pi) be the number of the occurrences of the generalized pattern 12\mn3\mn...\mnk12\mn3\mn...\mn k (respectively; 21\mn3\mn...\mnk21\mn3\mn...\mn k) in π\pi. In the present note, we study the distribution of the statistics ekπe_k\pi and fkπf_k\pi in a permutation avoiding the classical pattern 1\mn3\mn21\mn3\mn2. Also we present an applications, which relates the Narayana numbers, Catalan numbers, and increasing subsequences, to permutations avoiding the classical pattern 1\mn3\mn21\mn3\mn2 according to a given statistics on ekπe_k\pi, or on fkπf_k\pi.

Keywords

Cite

@article{arxiv.math/0110040,
  title  = {Continued fractions, statistics, and generalized patterns},
  author = {T. Mansour},
  journal= {arXiv preprint arXiv:math/0110040},
  year   = {2007}
}

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8 pages