login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A129554 Number of ways to place n+3 queens and 3 pawns 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, 0, 0, 1, 6, 66, 751, 9737, 131672, 1708295 (list; graph; refs; listen; history; internal format)
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, Journal of Combinatorial Mathematics and Combinatorial Computing, to appear.

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

Cf. A002562, A129553.

Sequence in context: A131519 A022024 A186666 * A165229 A127857 A127858

Adjacent sequences:  A129551 A129552 A129553 * A129555 A129556 A129557

KEYWORD

more,nonn

AUTHOR

R. Douglas Chatham (d.chatham(AT)moreheadstate.edu), Apr 20 2007

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 13 03:38 EST 2012. Contains 205435 sequences.