OFFSET
1,9
LINKS
R. D. Chatham, The N+k Queens Problem Page.
R. D. Chatham, M. Doyle, G. H. Fricke, J. Reitmann, R. D. Skaggs and M. Wolff, Independence and Domination Separation in Chessboard Graphs, J. Combin. Math. Combin. Comput. 68 (2009), 3-17.
EXAMPLE
a(4)=0 because when 7 queens are placed on a 4 X 4 board, at least two queens will be adjacent and therefore mutually attacking.
CROSSREFS
KEYWORD
more,nonn
AUTHOR
R. Douglas Chatham (d.chatham(AT)moreheadstate.edu), Apr 20 2007
STATUS
approved