39 search results - page 4 / 8 » On the enumeration of d-minimal permutations |
EJC
2008
13 years 7 months ago
2008
1 Rational functions and minimal factorizations of permutations Let f : C C be a rational function of degree n in one complex variable. A critical point of f is a point z C such...
DM
1999
13 years 7 months ago
1999
In this paper, we illustrate a method to enumerate two-dimensional directed animals, with compact sources, on both the square and the triangular lattice. We give a recursive descr...
COMBINATORICS
2000
13 years 7 months ago
2000
We find a generating function expressed as a continued fraction that enumerates ordered trees by the number of vertices at different levels. Several Catalan problems are mapped to...
COMBINATORICS
2000
13 years 7 months ago
2000
Two tournaments T1 and T2 on the same vertex set X are said to be switching equivalent if X has a subset Y such that T2 arises from T1 by switching all arcs between Y and its comp...
EJC
2010
13 years 7 months ago
2010
A classical result of Euler states that the tangent numbers are an alternating sum of Eulerian numbers. A dual result of Roselle states that the secant numbers can be obtained by a...