72 search results - page 1 / 15 » Permutations Avoiding Two Patterns of Length Three |
COMBINATORICS
2002
14 years 6 months ago
2002
COMBINATORICS
2006
14 years 6 months ago
2006
We present an algorithm for finding a system of recurrence relations for the number of permutations of length n that satisfy a certain set of conditions. A rewriting of these rela...
COMBINATORICS
2002
14 years 6 months ago
2002
: We generalize the notion of pattern avoidance to arbitrary functions on ordered sets, and consider specifically three scenarios for permutations: linear, cyclic and hybrid, the f...
DM
2008
14 years 6 months ago
2008
We give some new Wilf equivalences for signed patterns which allow the complete classification of signed patterns of lengths three and four. The problem is considered for pattern a...
DM
2007
14 years 6 months ago
2007
Several authors have examined connections between restricted permutations and Chebyshev polynomials of the second kind. In this paper we prove analogues of these results for color...