Pattern avoidance in matrices
Journal of integer sequences, Tome 8 (2005) no. 2
We generalize the concept of pattern avoidance from words to matrices, and consider specifically binary matrices avoiding the smallest non-trivial patterns. For all binary right angled patterns (0/1 subconfigurations with 3 entries, 2 in the same row and 2 in the same column) and all 2 x 2 binary patterns, we enumerate the $m$ x $n$ binary matrices avoiding the given pattern. For right angled patterns, and the all zeroes 2 x 2 pattern, we employ direct combinatorial considerations to obtain either explicit closed form formulas or generating functions; in the other cases, we use the transfer matrix method to derive an algorithm which gives, for any fixed $m$, a closed form formula in $n$. Some of these cases lead naturally to extremal problems of Ramsey type.
Classification :
05A05, 05A15, 05D10, 05C50
Keywords: binary matrices, Ramsey theory, forbidden subsequences, forbidden submatrices, transfer matrix
Keywords: binary matrices, Ramsey theory, forbidden subsequences, forbidden submatrices, transfer matrix
@article{JIS_2005__8_2_a4,
author = {Kitaev, Sergey and Mansour, Toufik and Vella, Antoine},
title = {Pattern avoidance in matrices},
journal = {Journal of integer sequences},
year = {2005},
volume = {8},
number = {2},
zbl = {1064.05015},
language = {en},
url = {http://geodesic.mathdoc.fr/item/JIS_2005__8_2_a4/}
}
Kitaev, Sergey; Mansour, Toufik; Vella, Antoine. Pattern avoidance in matrices. Journal of integer sequences, Tome 8 (2005) no. 2. http://geodesic.mathdoc.fr/item/JIS_2005__8_2_a4/