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A287762
Number of self-orthogonal diagonal Latin squares of order n.
4
1, 0, 0, 48, 480, 0, 322560, 46448640, 81587036160, 850065850368000
OFFSET
1,4
COMMENTS
A self-orthogonal diagonal Latin square is a diagonal Latin square orthogonal to its transpose.
A333671(n) <= a(n) <= A309599(n) <= A305571(n). - Eduard I. Vatutin, Apr 26 2020.
LINKS
E. I. Vatutin, Special types of diagonal Latin squares, Cloud and distributed computing systems in electronic control conference, within the National supercomputing forum (NSCF - 2022). Pereslavl-Zalessky, 2023. pp. 9-18. (in Russian)
E. I. Vatutin and A. D. Belyshev, About the number of self-orthogonal (SODLS) and doubly self-orthogonal diagonal Latin squares (DSODLS) of orders 1-10. High-performance computing systems and technologies. Vol. 4. No. 1. 2020. pp. 58-63. (in Russian)
E. Vatutin and A. Belyshev, Enumerating the Orthogonal Diagonal Latin Squares of Small Order for Different Types of Orthogonality, Communications in Computer and Information Science, Vol. 1331, Springer, 2020, pp. 586-597.
FORMULA
a(n) = A287761(n)*n!.
EXAMPLE
0 1 2 3 4 5 6 7 8 9
5 2 0 9 7 8 1 4 6 3
9 5 7 1 8 6 4 3 0 2
7 8 6 4 9 2 5 1 3 0
8 9 5 0 3 4 2 6 7 1
3 6 9 5 2 1 7 0 4 8
4 3 1 7 6 0 8 2 9 5
6 7 8 2 5 3 0 9 1 4
2 0 4 6 1 9 3 8 5 7
1 4 3 8 0 7 9 5 2 6
CROSSREFS
KEYWORD
nonn,more,hard
AUTHOR
Eduard I. Vatutin, May 31 2017
EXTENSIONS
a(10) from Eduard I. Vatutin, Mar 14 2020
a(10) corrected by Eduard I. Vatutin, Apr 24 2020
STATUS
approved