A279404 Independent domination number for queens' graph on an n X n toroidal board.

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

Table of n, a(n) for n=1..18.

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

Cf. A075324, A085801, A279402.

Sequence in context: A249018 A235052 A102066 * A072970 A276320 A011036

Adjacent sequences: A279401 A279402 A279403 * A279405 A279406 A279407

Keyword

nonn,hard,more

Author

Andrey Zabolotskiy, Dec 11 2016

Extensions

a(17)-a(18) from Andy Huchala, Mar 09 2024

Status

approved