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 A270858 Number of n X n checkered tori (see A179043) with at least one 0 and at least one 1 in each row and each column. 0
 0, 1, 14, 1446, 705366, 1304451482 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Let us denote by Qn the set of all n X n binary matrices with at least one 0 and at least one 1 in each row and each column. Let A,B belong to Qn. We will say that A and B are equivalent if B is obtained from A as a result of a sequential cyclic move of the last row or column at a first position. [Please rewrite that sentence!] It's easy to see that this defines an equivalence relation. The sequence gives the number of equivalence classes. The elements of the factor-set Qn/~ are relevant in the textile industry. LINKS Table of n, a(n) for n=1..6. K. Yordzhev, An example for the use of bitwise operations in programming, Mathematics and education in mathematics, v. 38 (2009), 196-202, also arXiv:1201.1468 [cs.OH], 2012. K. Yordzhev, H. Kostadinova, Mathematical Modelling in the Textile Industry Bulletin of Mathematical Sciences & Applications, Vol. 1, No. 1 (2012), pp. 20 -35. CROSSREFS Cf. A179043. Sequence in context: A204698 A240773 A131582 * A160246 A145693 A279326 Adjacent sequences: A270855 A270856 A270857 * A270859 A270860 A270861 KEYWORD nonn,more AUTHOR Krasimir Yordzhev, Mar 24 2016 STATUS approved

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Last modified September 7 13:22 EDT 2024. Contains 375730 sequences. (Running on oeis4.)