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
Johan de Ruiter, Table of n, a(n) for n = 1..40
J. de Ruiter, Counting Domino Coverings and Chessboard Cycles, 2010.
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
KEYWORD
nonn
AUTHOR
Johan de Ruiter, Dec 05 2010
STATUS
approved