%I A001230
%S A001230 0,0,9862,13267364410532
%N A001230 Number of closed knight's tours on a 2n X 2n chessboard.
%C A001230 No closed tour exists on an m X m board if m is odd.
%D A001230 N. D. Elkies and R. P. Stanley, The mathematical knight, Math. Intelligencer, 
               25 (No. 1, 2003), 22-34.
%D A001230 Brendan McKay (bdm(AT)cs.anu.edu.au), personal communication, Feb 03, 
               1997.
%D A001230 W. W. Rouse Ball, Mathematical Recreations and Essays (various editions), 
               Chap. 6.
%D A001230 I. Wegener, Branching Programs and Binary Decision Diagrams, SIAM, Philadelphia, 
               2000; see p. 369.
%H A001230 M. Loebbing and I. Wegener, <a href="http://www.combinatorics.org/Volume_3/
               volume3.html#R5">"The Number of Knight's Tours Equals 33,439,123,
               484,294 --- Counting with Binary Decision Diagrams"</a>. Electronic 
               Journal of Combinatorics, Vol. 3, Paper R5 [ Note the <a href="http:/
               /www.combinatorics.org/Volume_3/Comments/v3i1r1.html">comments</a> 
               at the end ].
%H A001230 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               KnightsTour.html">Knight's Tour</a>
%Y A001230 Sequence in context: A031597 A031777 A022199 this_sequence A103810 A072848 
               A145381
%Y A001230 Adjacent sequences: A001227 A001228 A001229 this_sequence A001231 A001232 
               A001233
%K A001230 nonn,hard,nice
%O A001230 1,3
%A A001230 N. J. A. Sloane (njas(AT)research.att.com), Martin Loebbing (loebbing(AT)ls2.informatik.uni-dortmund.de), 
               Brendan McKay (bdm(AT)cs.anu.edu.au)
%E A001230 Loebbing and Wegener give 33439123484294 for the 8 X 8 board. The value 
               given here is due to B. McKay and agrees with that given by Wegener 
               in his book.
%E A001230 Description and links corrected. - Max Alekseyev (maxale(AT)gmail.com), 
               Dec 09 2008