1,4

W. W. R. Ball and H. S. M. Coxeter,"Math'l Rec. and Essays," 13th Ed. Dover, p. 173.

C. Berge, Graphs and Hypergraphs, North-Holland, 1973; p. 304, Example 2.

Matthew D. Kearse and Peter B. Gibbons, "Computational Methods and New Results for Chessboard Problems", Australasian Journal of Combinatorics 23 (2001), 253-284.

M. A. Sainte-Lagu\"{e}, Les R\'{e}seaux (ou Graphes)}, M\'{e}morial des Sciences Math\'{e}matiques, Fasc. 18, Gauthier-Villars, Paris, 1926, p. 49.

a(8) = 5 queens attacking all squares of standard chessboard:

........

.....Q..

..Q.....

....Q...

......Q.

...Q....

........

........

A002567 gives number of solutions.

Sequence in context: A021303 A130250 A130253 this_sequence A134993 A011375 A119661

Adjacent sequences: A075321 A075322 A075323 this_sequence A075325 A075326 A075327

nonn

N. J. A. Sloane (njas(AT)research.att.com), Oct 16 2002