492 search results - page 72 / 99 » combinatorics 2006 |
74
Voted
COMBINATORICS
2002
14 years 9 months ago
2002
A map is a graph equipped with a circular order of edges around each vertex. These circular orders represent local planar embeddings. The genus of a map is the minimal genus of an...
COMBINATORICS
2002
14 years 9 months ago
2002
In 1906 Axel Thue showed how to construct an infinite non-repetitive (or squarefree) word on an alphabet of size 3. Since then this result has been rediscovered many times and ext...
COMBINATORICS
2002
14 years 9 months ago
2002
Several authors have examined connections between permutations which avoid 132, continued fractions, and Chebyshev polynomials of the second kind. In this paper we prove analogues...
COMBINATORICS
2002
14 years 9 months ago
2002
Knowing the excluded minors for a minor-closed matroid property provides a useful alternative characterization of that property. It has been shown in [R. Hall, J. Oxley, C. Semple...
78
Voted
COMBINATORICS
2002
14 years 9 months ago
2002
Let In() denote the number of involutions in the symmetric group Sn which avoid the permutation . We say that two permutations , Sj may be exchanged if for every n, k, and order...