login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A175881 Number of closed Knight's tours on a 6 X n board. 4
0, 0, 0, 0, 8, 9862, 1067638, 55488142, 3374967940, 239187240144, 15360134570696, 964730606632516, 61989683445413228, 4005716717182224826, 255967892553030600920, 16378998506224697063588, 1050504687249683771795632, 67351449674771471216148786, 4314151246752166099728445868 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,5
COMMENTS
Could you please say how you calculated these numbers? - N. J. A. Sloane, Dec 05 2010?
I kept track of pairs of loose ends within the two rightmost columns of a 6 X n board, assuming that everything to the left of these two columns is fully connected and that there are no cycles (or one if this is a final state). Next I added a new column and connected it to the rightmost two columns in all ways such that there are no cycles formed(or one if this results in a final state) and the leftmost column in the current state is fully connected and can be dropped. From this followed a transition matrix. I can provide a reference to my writeup once it is completed and has been accepted by my supervisor. - Johan de Ruiter, Dec 05 2010
LINKS
EXAMPLE
The smallest 6 X n board admitting a closed Knight's tour is the 6 X 5, on which there are 8 such tours.
CROSSREFS
A070030 deals with 3 X 2n boards, A175855 with 5 X 2n boards.
Sequence in context: A230570 A055308 A188890 * A165429 A343475 A242852
KEYWORD
nonn
AUTHOR
Johan de Ruiter, Dec 05 2010
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 18 22:56 EDT 2024. Contains 370952 sequences. (Running on oeis4.)