

A279404


Independent domination number for queens' graph on an n X n toroidal board.


4



1, 1, 1, 2, 5, 4, 5, 4, 5, 5, 5, 6, 7, 7, 5, 8
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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.


LINKS



FORMULA

a(3*n) = n if n = 1, 5, 7, 11 (mod 12).


CROSSREFS



KEYWORD

nonn,hard,more


AUTHOR



STATUS

approved



