Hostname: page-component-848d4c4894-xfwgj Total loading time: 0 Render date: 2024-06-23T13:29:22.687Z Has data issue: false hasContentIssue false

DIVISION SUDOKUS: INVARIANTS, ENUMERATION, AND MULTIPLE PARTITIONS

Published online by Cambridge University Press:  02 October 2019

ALEŠ DRÁPAL
Affiliation:
Department of Mathematics, Charles University, Sokolovská 83, 186 75, Praha 8, Czech Republic e-mail: drapal@karlin.mff.cuni.cz
PETR VOJTĚCHOVSKÝ
Affiliation:
Department of Mathematics, University of Denver, 2390 S. York St, Denver, CO 80208, USA e-mail: petr@math.du.edu

Abstract

A division sudoku is a latin square whose all six conjugates are sudoku squares. We enumerate division sudokus up to a suitable equivalence, introduce powerful invariants of division sudokus, and also study latin squares that are division sudokus with respect to multiple partitions at the same time. We use nearfields and affine geometry to construct division sudokus of prime power rank that are rich in sudoku partitions.

Keywords

Type
Research Article
Copyright
© Glasgow Mathematical Journal Trust 2019

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bailey, R. A., Cameron, P. J. and Connelly, R., Sudoku, gerechte designs, resolutions, affine space, spreads, reguli, and Hamming codes, Amer. Math. Month. 115(5) (2008), 383404.CrossRefGoogle Scholar
Belousov, V. D., The group associated with a quasigroup (Russian), Mat. Issled. 4/3 (1969), 2139.Google Scholar
Bruck, R. H., A survey of binary systems, Ergebnisse der Mathematik und ihrer Grenzgebiete, Neue Folge, Heft 20 (Springer Verlag, Berlin-Göttingen-Heidelberg, 1958).CrossRefGoogle Scholar
Cameron, P. J., Hilton, A. J. W. and Vaughan, E. R., An analogue of Ryser’s theorem for partial Sudoku squares, J. Combin. Math. Combin. Comput . 80 (2012), 4769.Google Scholar
Drápal, A. and Lisoně, P., Extreme nonassociativity via nearfields, accepted to Finite Fields and Applications.Google Scholar
Drápal, A. and Valent, V., High nonassociativity in order 8 and an associative index estimate, J. Combin. Des . 27 (2019), 205228.Google Scholar
Drápal, A. and Valent, V., Extreme nonassociativity in order nine and beyond, J. Combin. Des., accepted.Google Scholar
Colbourn, C. J. and Dinitz, J. H. (eds.), Handbook of combinatorial designs, Discrete Mathematics and its Applications (Boca Raton), 2nd edition (Chapman and Hall/CRC, Boca Raton, FL, 2007).Google Scholar
The, GAP Group, GAP – Groups, Algorithm s, and Programming, Version 4.6.3 (2013). http://www.gap-system.org.Google Scholar
Keedwell, A. D., Constructions of complete sets of orthogonal diagonal Sudoku squares, Australas. J. Combin. 47 (2010), 227238.Google Scholar
Kepka, T., A note on associative triples of elements in cancellation groupoids, Comment. Math. Univ. Carolin. 21 (1980), 479487.Google Scholar
Lambert, T. A. and Whitlock, P. A., Generalizing Sudoku to three dimensions, Monte Carlo Methods Appl . 16(3–4) (2010), 251263.CrossRefGoogle Scholar
Lorch, J., Magic squares and sudoku, Amer. Math. Month. 119(9) (2012), 759770.CrossRefGoogle Scholar
McGuire, G., Tugemann, B. and Civario, G., There is no 16-clue Sudoku: solving the Sudoku minimum number of clues problem via hitting set enumeration, Exp. Math. 23(2) (2014), 190217.CrossRefGoogle Scholar
Nagy, G. P. and Vojtěchovský, P., LOOPS: Computing with quasigroups and loops in GAP. Available at http://www.math.du.edu/~petr/loops.Google Scholar
Pedersen, R. M. and Vis, T. L., Sets of mutually orthogonal Sudoku Latin squares, College Math. J. 40(3) (2009), 174180.Google Scholar
Stanovský, D. and Vojtěchovský, P., Commutator theory for loops, J. Algebra 399 (2014), 290322.CrossRefGoogle Scholar
Stein, S. K., Homogeneous quasigroups, Pacific J. Math . 14 (1964), 10911102.CrossRefGoogle Scholar
Zassenhaus, H., Über endliche Fastkörper (German), Abh. Math. Sem. Univ. Hamburg 11(1) (1935) 187220.CrossRefGoogle Scholar