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Number of doubly self-orthogonal diagonal Latin squares of order n.
2

%I #25 Jan 29 2023 17:51:38

%S 1,0,0,48,480,0,322560,46448640,10381271040,0

%N Number of doubly self-orthogonal diagonal Latin squares of order n.

%C A doubly self-orthogonal diagonal Latin square (DSODLS) is a diagonal Latin square orthogonal to its transpose and antitranspose.

%C a(n) <= A287762(n) <= A309599(n) <= A305571(n). - _Eduard I. Vatutin_, Jun 06 2020

%H R. Lu, S. Liu, and J. Zhang, <a href="https://doi.org/10.1007/978-3-642-23786-7_41">Searching for Doubly Self-orthogonal Latin Squares</a>. Lecture Notes in Computer Science 6876 (2011), 538-545.

%H E. I. Vatutin, <a href="https://vk.com/wall162891802_1105">About the number of DSODLS of orders 1-10</a> (in Russian).

%H E. I. Vatutin, <a href="http://evatutin.narod.ru/evatutin_dsodls_1_to_10.zip">List of all main classes of doubly self-orthogonal diagonal Latin squares of orders 1-10</a>.

%H E. I. Vatutin and A. D. Belyshev, <a href="http://evatutin.narod.ru/evatutin_sodls_and_dsodls_1_to_10.pdf">About the number of self-orthogonal (SODLS) and doubly self-orthogonal diagonal Latin squares (DSODLS) of orders 1-10</a>. High-performance computing systems and technologies. Vol. 4. No. 1. 2020. pp. 58-63. (in Russian)

%H E. Vatutin and A. Belyshev, <a href="https://www.springerprofessional.de/en/enumerating-the-orthogonal-diagonal-latin-squares-of-small-order/18659992">Enumerating the Orthogonal Diagonal Latin Squares of Small Order for Different Types of Orthogonality</a>, Communications in Computer and Information Science, Vol. 1331, Springer, 2020, pp. 586-597.

%H <a href="/index/La#Latin">Index entries for sequences related to Latin squares and rectangles</a>.

%e 0 1 2 3 4 5 6 7 8

%e 2 4 3 0 7 6 8 1 5

%e 4 6 7 1 8 2 3 5 0

%e 8 3 5 6 0 7 1 2 4

%e 7 8 1 4 5 3 0 6 2

%e 3 7 0 2 1 8 5 4 6

%e 1 5 4 7 6 0 2 8 3

%e 5 0 6 8 2 1 4 3 7

%e 6 2 8 5 3 4 7 0 1

%Y Cf. A287762, A309599.

%K nonn,more,hard

%O 1,4

%A _Eduard I. Vatutin_, Apr 01 2020