Finite automata and pattern avoidance in words
| dc.creator | Brändén, Petter | |
| dc.creator | Mansour, Toufik | |
| dc.date | 2003-09-17 | |
| dc.date.accessioned | 2026-07-07T05:01:11Z | |
| dc.date.available | 2026-07-07T05:01:11Z | |
| dc.description | We say that a word $w$ on a totally ordered alphabet avoids the word $v$ if there are no subsequences in $w$ order-equivalent to $v$. In this paper we suggest a new approach to the enumeration of words on at most $k$ letters avoiding a given pattern. By studying an automaton which for fixed $k$ generates the words avoiding a given pattern we derive several previously known results for these kind of problems, as well as many new. In particular, we give a simple proof of the formula \cite{Reg1998} for exact asymptotics for the number of words on $k$ letters of length $n$ that avoids the pattern $12...(\ell+1)$. Moreover, we give the first combinatorial proof of the exact formula \cite{Burstein} for the number of words on $k$ letters of length $n$ avoiding a three letter permutation pattern. | |
| dc.description | 17 pages, 1 figures, 2 tables | |
| dc.identifier | https://arxiv.org/abs/math/0309269 | |
| dc.identifier | http://arxiv.org/abs/math/0309269 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/68584 | |
| dc.subject | Combinatorics | |
| dc.subject | 05A05; 05A15; 68Q45 | |
| dc.title | Finite automata and pattern avoidance in words | |
| dc.type | text |