Displaying 501 – 520 of 852

Showing per page

On a New Approach to Williamson's Generalization of Pólya's Enumeration Theorem

Iliev, Valentin (2000)

Serdica Mathematical Journal

Pólya’s fundamental enumeration theorem and some results from Williamson’s generalized setup of it are proved in terms of Schur- Macdonald’s theory (S-MT) of “invariant matrices”. Given a permutation group W ≤ Sd and a one-dimensional character χ of W , the polynomial functor Fχ corresponding via S-MT to the induced monomial representation Uχ = ind|Sdv/W (χ) of Sd , is studied. It turns out that the characteristic ch(Fχ ) is the weighted inventory of some set J(χ) of W -orbits in the integer-valued hypercube...

On binary trees and Dyck paths

A. Panayotopoulos, A. Sapounakis (1995)

Mathématiques et Sciences Humaines

A bijection between the set of binary trees with n vertices and the set of Dyck paths of length 2n is obtained. Two constructions are given which enable to pass from a Dyck path to a binary tree and from a binary tree to a Dyck path.

On binary trees and permutations

A. Panayotopoulos, A. Sapounakis (1992)

Mathématiques et Sciences Humaines

Every binary tree is associated to a permutation with repetitions, which determines it uniquely. Two operations are introduced and used for the construction of the set of all binary trees. The set of all permutations which correspond to a given binary tree is determined and its cardinal number is evaluated.

Currently displaying 501 – 520 of 852