39 search results - page 5 / 8 » On the enumeration of d-minimal permutations |
JCT
2010
13 years 5 months ago
2010
Abstract. We present bijections between four classes of combinatorial objects. Two of them, the class of unlabeled (2 + 2)-free posets and a certain class of involutions (or chord ...
EJC
2006
13 years 7 months ago
2006
Abstract. A leaf of a plane tree is called an old leaf if it is the leftmost child of its parent, and it is called a young leaf otherwise. In this paper we enumerate plane trees wi...
COMBINATORICS
2002
13 years 7 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...
JCT
2011
13 years 2 months ago
2011
The Baxter number Bn can be written as Bn = n k=0 Θk,n−k−1 with Θk,ℓ = 2 (k + 1)2 (k + 2) k + ℓ k k + ℓ + 1 k k + ℓ + 2 k . These numbers have first appeared in the...
CORR
2004
Springer
13 years 7 months ago
2004
Springer
Abstract. We investigate two associative products over the ring of symmetric functions related to the intransitive and Cartesian products of permutation groups. As an application, ...