An improved lower bound for domination numbers of the Queen's graph

The queen's graph Q(n) has the squares of the n x n chessboard as its vertices; two squares are adjacent if they are in the same row, column, or diagonal. Let gamma(Q(n)) be the minimum size of a dominating set of Q(n) It has been proved that gamma(Q(n)) >= (n - 1)/2 for all n. Known dominating sets imply that gamma(Q(n)) = (n - 1)/2 for n = 3,11. We show that gamma(Q(n)) = (n - 1)/2 only for n = 3,11, and thus that gamma(Q(n)) >= inverted right perpendicular n/2 inverted left perpendicular for all other positive integers n.