Geodesic
Wilf classes of pairs of permutations of length 4
The electronic journal of combinatorics, Tome 12 (2005)
Cet article a éte moissonné depuis la source The Electronic Journal of Combinatorics website

Voir la notice de l'article

$S_n(\pi_1,\pi_2,\dots, \pi_r)$ denotes the set of permutations of length $n$ that have no subsequence with the same order relations as any of the $\pi_i$. In this paper we show that $|S_n(1342,2143)|=|S_n(3142,2341)|$ and $|S_n(1342,3124)|=|S_n(1243,2134)|$. These two facts complete the classification of Wilf-equivalence classes for pairs of permutations of length four. In both instances we exhibit bijections between the sets using the idea of a "block", and in the former we find a generating function for $|S_n(1342,2143)|$.
DOI : 10.37236/1922
Classification : 05A05, 05A15
Mots-clés : Wilf equivalence 
@article{10_37236_1922,
     author = {Ian Le},
     title = {Wilf classes of pairs of permutations of length 4},
     journal = {The electronic journal of combinatorics},
     year = {2005},
     volume = {12},
     doi = {10.37236/1922},
     zbl = {1081.05002},
     url = {http://geodesic.mathdoc.fr/articles/10.37236/1922/}
}
TY  - JOUR
AU  - Ian Le
TI  - Wilf classes of pairs of permutations of length 4
JO  - The electronic journal of combinatorics
PY  - 2005
VL  - 12
UR  - http://geodesic.mathdoc.fr/articles/10.37236/1922/
DO  - 10.37236/1922
ID  - 10_37236_1922
ER  - 
%0 Journal Article
%A Ian Le
%T Wilf classes of pairs of permutations of length 4
%J The electronic journal of combinatorics
%D 2005
%V 12
%U http://geodesic.mathdoc.fr/articles/10.37236/1922/
%R 10.37236/1922
%F 10_37236_1922
Ian Le. Wilf classes of pairs of permutations of length 4. The electronic journal of combinatorics, Tome 12 (2005). doi: 10.37236/1922

Cité par Sources :