login
A279404
Independent domination number for queens' graph on an n X n toroidal board.
6
1, 1, 1, 2, 5, 4, 5, 4, 5, 5, 5, 6, 7, 7, 5, 8, 9, 10
OFFSET
1,4
COMMENTS
That is, the minimal number of queens needed to cover an n X n toroidal chessboard so that every square either has a queen on it or is under attack by a queen, but not both.
A279402(n) <= a(n) <= A085801(n).
LINKS
Andy Huchala, Python program.
Christina M. Mynhardt, Upper bounds for the domination numbers of toroidal queens graphs, Discussiones Mathematicae Graph Theory, 23 (2003), 163-175.
FORMULA
a(3*n) = n if n = 1, 5, 7, 11 (mod 12).
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Andrey Zabolotskiy, Dec 11 2016
EXTENSIONS
a(17)-a(18) from Andy Huchala, Mar 09 2024
STATUS
approved