OFFSET
1,3
COMMENTS
For odd n > 1 the only symmetry possible is rotation by 180 degrees. For even n the only symmetries are reflections either horizontally or vertically. - Andrew Howroyd, Apr 15 2016
LINKS
J.-M. Mayer, C. Guez and J. Dayantis, Exact computer enumeration of the number of Hamiltonian paths in small square plane lattices, Physical Review B, Vol. 42 Number 1, 1990.
CROSSREFS
KEYWORD
nonn,walk,hard
AUTHOR
Luca Petrone, Dec 18 2015
EXTENSIONS
a(9)-a(15) from Andrew Howroyd, Apr 15 2016
STATUS
approved