Number of open directed king's tours on the n X n board.
Table of n, a(n) for n=1..5.
Eric Weisstein's World of Mathematics, King's Tour Graph
Index entries for sequences related to graphs, Hamiltonian
Cf. A140521, A096969, A137891.
Sequence in context: A239815 A062528 A175604 * A204559 A078522 A208792
Adjacent sequences: A158648 A158649 A158650 * A158652 A158653 A158654
Eric W. Weisstein, Mar 23 2009
a(5) from Max Alekseyev, May 03 2009