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A279405
Peaceable coexisting armies of queens on a torus: the maximum number m such that m white queens and m black queens can coexist on an n X n toroidal chessboard without attacking each other.
5
0, 0, 0, 2, 2, 4, 4, 8, 7, 12, 10, 18
OFFSET
1,4
COMMENTS
a(n) <= A250000(n).
a(n) is maximal m such that A279406(n,m) >= m.
LINKS
Andy Huchala, Python program.
Katie Clinch, Matthew Drescher, Tony Huynh, and Abdallah Saffidine, Constructions, bounds, and algorithms for peaceable queens, arXiv:2406.06974 [math.CO], 2024. See p. 1.
EXAMPLE
A solution for n=6:
......
.W...W
...B..
..B.B.
...B..
.W...W
CROSSREFS
Sequence in context: A191234 A225373 A138219 * A100835 A347444 A120541
KEYWORD
nonn,hard,more
AUTHOR
Andrey Zabolotskiy, Dec 11 2016
EXTENSIONS
a(10)-a(12) from Andy Huchala, Mar 10 2024
STATUS
approved