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A note on the determinant of a Toeplitz-Hessenberg matrix

Mircea Merca (2013)

Special Matrices

The nth-order determinant of a Toeplitz-Hessenberg matrix is expressed as a sum over the integer partitions of n. Many combinatorial identities involving integer partitions and multinomial coefficients can be generated using this formula.

A note on the number of squares in a partial word with one hole

Francine Blanchet-Sadri, Robert Mercaş (2009)

RAIRO - Theoretical Informatics and Applications

A well known result of Fraenkel and Simpson states that the number of distinct squares in a word of length n is bounded by 2n since at each position there are at most two distinct squares whose last occurrence starts. In this paper, we investigate squares in partial words with one hole, or sequences over a finite alphabet that have a “do not know” symbol or “hole”. A square in a partial word over a given alphabet has the form uv where u is compatible with v, and consequently, such square is...

A partition of the Catalan numbers and enumeration of genealogical trees

Rainer Schimming (1996)

Discussiones Mathematicae Graph Theory

A special relational structure, called genealogical tree, is introduced; its social interpretation and geometrical realizations are discussed. The numbers C n , k of all abstract genealogical trees with exactly n+1 nodes and k leaves is found by means of enumeration of code words. For each n, the C n , k form a partition of the n-th Catalan numer Cₙ, that means C n , 1 + C n , 2 + . . . + C n , n = C .

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