

A287649


Number of symmetric diagonal Latin squares of order 2n with constant first string.


1




OFFSET

1,2


LINKS

Table of n, a(n) for n=1..5.
E. I. Vatutin, Discussion about properties of diagonal Latin squares at forum.boinc.ru (in Russian)
E. I. Vatutin, S. E. Kochemazov, O. S. Zaikin, Estimating of combinatorial characteristics for diagonal Latin squares, Recognition — 2017 (2017), pp. 98100 (in Russian)
E. I. Vatutin, Discussion about properties of diagonal Latin squares at forum.boinc.ru, continuation (in Russian)


EXAMPLE

Horizontal plane 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
Vertical plane 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


CROSSREFS

Cf. A003191, A287650.
Sequence in context: A139772 A092238 A228252 * A229352 A229815 A273498
Adjacent sequences: A287646 A287647 A287648 * A287650 A287651 A287652


KEYWORD

nonn,more


AUTHOR

Eduard I. Vatutin, May 29 2017


EXTENSIONS

a(5) calculated and added by Eduard I. Vatutin, S. E. Kochemazov and O. S. Zaikin, Jun 15 2017


STATUS

approved



