A238819 Number of Hamiltonian cycles on 4n+2 X 4n+2 grid with at least 90-degree rotational symmetry.

1, 2, 204, 510718, 31008619522, 43911490791183200, 1424639466911800364132674, 1048492580133908850434091619741314

Offset

0,2

Links

Table of n, a(n) for n=0..7.

Ed Wynn, Enumeration of nonisomorphic Hamiltonian cycles on square grid graphs, arXiv preprint arXiv:1402.0545 [math.CO], 2014.

Crossrefs

Cf. A003763.

Sequence in context: A349982 A209185 A216608 * A110899 A363461 A281126

Adjacent sequences: A238816 A238817 A238818 * A238820 A238821 A238822

Keyword

nonn,more

Author

N. J. A. Sloane, Mar 05 2014

Extensions

a(5)-a(7) from Andrew Howroyd, Apr 06 2016

Status

approved