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).

0, 0, 0, 0, 0, 2, 3, 16, 52, 286, 1403, 8214, 54756, 389833, 2923757, 22932960, 184339572

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

For n=6 the a(6)=2 solutions are
 . . Q . . .    . . Q . . .
 Q . P . . Q    Q . P . . Q
 . . . Q . .    . . Q . . .
 . Q . . . .    . . . . Q .
 . . . . Q .    . Q . . . .
 . . Q . . .    . . . Q . .

Crossrefs

Cf. A103330, A002562, A368061.

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