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We (1) determine the number of Latin rectangles with 11 columns and each possible number of rows, including the Latin squares of order~11, (2) answer some questions of Alter by showing that the number of reduced Latin squares of order $n$…

Combinatorics · Mathematics 2009-09-14 Brendan D. McKay , Ian M. Wanless

We prove that, for all even $n\geq10$, there exists a latin square of order $n$ with at least one transversal, yet all transversals coincide on $ \big\lfloor n/6 \big\rfloor$ entries. These latin squares have at least $ 19 n^2/36 + O(n)$…

Combinatorics · Mathematics 2024-12-18 Afsane Ghafari , Ian M. Wanless

To get another from a given latin square, we have to change at least 4 entries. We show how to find these entries and how to change them.

Combinatorics · Mathematics 2019-02-18 I. I. Deriyenko

Given two integers $m$ and $n$ with $m\leq n$, a Latin rectangle of size $m\times n$ is a bi-dimensional array with $m$ rows and $n$ columns filled with symbols from an alphabet with $n$ symbols, such that each row contains a permutation of…

Combinatorics · Mathematics 2015-09-03 N. Astromujoff , M. Matamala

We show how to generate an expression for the number of k-line Latin rectangles for any k. The computational complexity of the resulting expression, as measured by the number of additions and multiplications required to evaluate it, is on…

Combinatorics · Mathematics 2007-05-23 Peter G. Doyle

Two latin squares are orthogonal if, when they are superimposed, every ordered pair of symbols appears exactly once. This definition extends naturally to `incomplete' latin squares each having a hole on the same rows, columns, and symbols.…

Combinatorics · Mathematics 2014-10-27 Peter J. Dukes , Christopher M. van Bommel

Let m and n be integers, $2 \leq m \leq n$. An m by n array consists of mn cells, arranged in m rows and n columns, and each cell contains exactly one symbol. A transversal of an array consists of m cells, one from each row and no two from…

Combinatorics · Mathematics 2007-05-23 Sherman K. Stein

We derive necessary and sufficient conditions for there to exist a latin square of order $n$ containing two subsquares of order $a$ and $b$ that intersect in a subsquare of order $c$. We also solve the case of two disjoint subsquares. We…

Combinatorics · Mathematics 2015-09-21 Joshua M. Browning , Petr Vojtěchovský , Ian M. Wanless

Constructive and nonconstructive techniques are employed to enumerate Latin squares and related objects. It is established that there are (i) 2036029552582883134196099 main classes of Latin squares of order 11; (ii)…

Combinatorics · Mathematics 2010-02-08 Alexander Hulpke , Petteri Kaski , Patric R. J. Östergård

A Latin square $L(n,k)$ is a square of order $n$ with its entries colored with $k$ colors so that all the entries in a row or column have different colors. Let $d(L(n,k))$ be the minimal number of colored entries of an $n \times n$ square…

Combinatorics · Mathematics 2007-05-23 Karola Meszaros

A Latin square has six conjugate Latin squares obtained by uniformly permuting its (row, column, symbol) triples. We say that a Latin square has conjugate symmetry if at least two of its six conjugates are equal. We enumerate Latin squares…

Combinatorics · Mathematics 2021-12-09 Brendan D. McKay , Ian M. Wanless

We show that any partial Latin square of order $n$ can be embedded in a Latin square of order at most $16n^2$ which has at least $2n$ mutually orthogonal mates. We also show that for any $t\geq 2$, a pair of orthogonal partial Latin squares…

Combinatorics · Mathematics 2018-11-13 Diane M. Donovan , Mike Grannell , Emine Şule Yazıcı

Two Latin squares of order $n$ are $r$-orthogonal if, when superimposed, there are exactly $r$ distinct ordered pairs. The spectrum of all values of $r$ for Latin squares of order $n$ is known. A Latin square $A$ of order $n$ is…

Discrete Mathematics · Computer Science 2024-02-15 Sergey Bereg

This paper provides an in-depth analysis of how computational algebraic geometry can be used to deal with the problem of counting and classifying $r\times s$ partial Latin rectangles based on $n$ symbols of a given size, shape, type or…

Combinatorics · Mathematics 2019-01-08 Raúl M. Falcón

We use a greedy probabilistic method to prove that for every $\epsilon > 0$, every $m\times n$ Latin rectangle on $n$ symbols has an orthogonal mate, where $m=(1-\epsilon)n$. That is, we show the existence of a second Latin rectangle such…

Combinatorics · Mathematics 2007-05-23 Roland Häggkvist , Anders Johansson

Similar to how standard Young tableaux represent paths in the Young lattice, Latin rectangles may be use to enumerate paths in the poset of semi-magic squares with entries zero or one. The symmetries associated to determinant preserve this…

Combinatorics · Mathematics 2022-02-15 Robert W. Donley, , Won Geun Kim

The chromatic number of a Latin square is the least number of partial transversals which cover its cells. This is just the chromatic number of its associated Latin square graph. Although Latin square graphs have been widely studied as…

Combinatorics · Mathematics 2016-10-31 Nazli Besharati , Luis Goddyn , E. S. Mahmoodian , M. Mortezaeefar

Let $m \leq n \leq k$. An $m \times n \times k$ 0-1 array is a Latin box if it contains exactly $mn$ ones, and has at most one $1$ in each line. As a special case, Latin boxes in which $m = n = k$ are equivalent to Latin squares. Let…

Combinatorics · Mathematics 2019-02-12 Zur Luria , Michael Simkin

For $\mu$ given latin squares of order $n$, they have {\sf $k$ intersection} when they have $k$ identical cells and $n^2-k$ cells with mutually different entries. For each $n\geq 1$ the set of integers $k$ such that there exist $\mu$ latin…

Combinatorics · Mathematics 2015-09-17 P. Adams , E. S. Mahmoodian , H. Minooei , M. Mohammadi Nevisi

Consider a partial Latin square $P$ where the first two rows and first three columns are completely filled, and every other cell of $P$ is empty. It has been conjectured that all such partial Latin squares of order at least $8$ are…

Combinatorics · Mathematics 2020-05-19 Carl Johan Casselgren , Herman Göransson
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