8 search results - page 1 / 2 » The Initial Involution Patterns of Permutations |
COMBINATORICS
2007
13 years 4 months ago
2007
For a permutation π = π1π2 · · · πn ∈ Sn and a positive integer i ≤ n, we can view π1π2 · · · πi as an element of Si by order-preserving relabeling. The j-set of ...
DM
2008
13 years 4 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...
COMBINATORICS
2002
13 years 4 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...
COMBINATORICS
2004
13 years 4 months ago
2004
We study the distribution of the statistics `number of fixed points' and `number of excedances' in permutations avoiding subsets of patterns of length 3. We solve all th...
DM
2007
13 years 4 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...