A222202 Number of ways to cover the 2n X 2n grid graph by vertex disjoint cycles.

1, 18, 13903, 360783593, 303872744726644, 8217125138015950451626, 7095967027221343377167292602835, 195081705501438193439250404333039349462635, 170400931523966165754313513175663906434875251822099185, 4722705723996809689481769489662532396060449405036901391459114641198

Offset

1,2

Links

Andrew Howroyd, Table of n, a(n) for n = 1..12

Peter Tittmann, Enumeration in graphs: counting Hamiltonian cycles [Archived link]

Crossrefs

Cf. A222203, A222204.

Sequence in context: A213402 A248804 A060617 * A201986 A153301 A129042

Adjacent sequences: A222199 A222200 A222201 * A222203 A222204 A222205

Keyword

nonn

Author

N. J. A. Sloane, Feb 14 2013

Extensions

a(10)-a(12) from Andrew Howroyd, Nov 16 2015

Status

approved