Abstract
Recently, Babson and Steingrímsson (see [BS]) introduced generalized permutations patterns that allow the requirement that two adjacent letters in a pattern must be adjacent in the permutation. Following [BCS], let e kπ (respectively; fkπ) be the number of the occurrences of the generalized pattern 12-3-...-k (respectively; 21-3-...-k) in π. In the present note, we study the distribution of the statistics e kπ and fkπ in a permutation avoiding the classical pattern 1-3-2. We also present some applications of our results which relate the enumeration of permutations avoiding the classical pattern 1-3-2 according to the statistics ek and fk to Narayana numbers and Catalan numbers.
Original language | English |
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Pages (from-to) | 265-274 |
Number of pages | 10 |
Journal | Ars Combinatoria |
Volume | 70 |
State | Published - Jan 2004 |
Externally published | Yes |
ASJC Scopus subject areas
- General Mathematics