OFFSET
1,2
COMMENTS
That is, the minimal number of knights needed to cover an n X n toroidal chessboard so that every square either has a knight on it, or is under attack by a knight, or both.
REFERENCES
John J. Watkins, Across the Board: The Mathematics of Chessboard Problem, Princeton University Press, 2004, pages 140-144.
LINKS
Andy Huchala, Python program.
EXAMPLE
For an 8 X 8 board, the solution is:
N . . . . . . N
. . . . . . . .
. . N . . N . .
. . . . . . . .
. . . N N . . .
. . . . . . . .
. N . . . . N .
. . . . . . . .
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Andrey Zabolotskiy, Dec 12 2016
EXTENSIONS
a(9)-a(16) from Andy Huchala, Mar 03 2024
STATUS
approved