

A001230


Number of undirected closed knight's tours on a 2n X 2n chessboard.


12




OFFSET

1,3


COMMENTS

No closed tour exists on an m X m board if m is odd.


REFERENCES

Brendan McKay, personal communication, Feb 03, 1997.
W. W. Rouse Ball, Mathematical Recreations and Essays (various editions), Chap. 6.
I. Wegener, Branching Programs and Binary Decision Diagrams, SIAM, Philadelphia, 2000; see p. 369.


LINKS



MATHEMATICA

Table[Length[FindHamiltonianCycle[KnightTourGraph[2 n, 2 n], All]], {n, 3}]


CROSSREFS



KEYWORD

nonn,hard,more,nice


AUTHOR



EXTENSIONS

Loebbing and Wegener incorrectly gave 33439123484294 for the 8 X 8 board. The value given here is due to Brendan McKay and agrees with that given by Wegener in his book.


STATUS

approved



