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A340546
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Number of main classes of one-plane symmetric diagonal Latin squares of order 2n.
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4
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OFFSET
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1,3
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COMMENTS
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A one-plane symmetric diagonal Latin square is a vertically or horizontally symmetric diagonal Latin square (see A296060). Such diagonal Latin squares do not exist for odd orders > 1.
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LINKS
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Table of n, a(n) for n=1..4.
Eduard I. Vatutin, On the number of main classes of one plane and double plane symmetric diagonal Latin squares of orders 1-8 (in Russian).
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EXAMPLE
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A horizontally symmetric diagonal Latin square:
0 1 2 3 4 5
4 2 0 5 3 1
5 4 3 2 1 0
2 5 4 1 0 3
3 0 1 4 5 2
1 3 5 0 2 4
A vertically symmetric diagonal Latin square:
0 1 2 3 4 5
4 2 5 0 3 1
3 5 1 2 0 4
5 3 0 4 1 2
2 4 3 1 5 0
1 0 4 5 2 3
Both are one-plane symmetric diagonal Latin squares.
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CROSSREFS
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Cf. A287649, A292516, A293777, A293778, A296060, A296061.
Sequence in context: A167748 A203755 A285692 * A343700 A086563 A023328
Adjacent sequences: A340543 A340544 A340545 * A340547 A340548 A340549
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KEYWORD
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nonn,more,hard,bref
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AUTHOR
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Eduard I. Vatutin, Jan 11 2021
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STATUS
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approved
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