|
|
A103331
|
|
Number of ways to place n+1 queens and a pawn on an n X n board so that no two queens attack each other (symmetric solutions count only once).
|
|
1
|
|
|
0, 0, 0, 0, 0, 2, 3, 16, 52, 286, 1403, 8214, 54756, 389833, 2923757, 22932960, 184339572
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,6
|
|
LINKS
|
Table of n, a(n) for n=1..17.
R. D. Chatham, The N+k Queens Problem Page.
R. D. Chatham, G. H. Fricke and R. D. Skaggs, The Queens Separation Problem, Utilitas Mathematica 69 (2006), 129-141.
R. D. Chatham, M. Doyle, G. H. Fricke, J. Reitmann, R. D. Skaggs and M. Wolff, Indepe ndence and Domination Separation in Chessboard Graphs, Journal of Combinatorial Mathematics and Combinatorial Computing, to appear.
|
|
EXAMPLE
|
a(4) = 0 since when 5 queens are placed on a 4 X 4 board, at least two of them will be adjacent and therefore mutually attacking.
|
|
CROSSREFS
|
Cf. A103330, A002562.
Sequence in context: A012358 A012700 A012705 * A052506 A355229 A052858
Adjacent sequences: A103328 A103329 A103330 * A103332 A103333 A103334
|
|
KEYWORD
|
more,nonn
|
|
AUTHOR
|
R. Douglas Chatham (d.chatham(AT)moreheadstate.edu), Jan 31 2005
|
|
EXTENSIONS
|
More terms from R. Douglas Chatham (d.chatham(AT)moreheadstate.edu), Feb 15 2005, Apr 20 2007
|
|
STATUS
|
approved
|
|
|
|