A222203 Number of ways to cover the n X n+1 grid graph by vertex disjoint cycles.

1, 3, 54, 1140, 99051, 13049563, 6044482889, 4738211572702, 11986520595161863, 54755153078468134960, 764291947227525464744293, 20119942924108379011391597989, 1558052539448513320447263528275071, 234788223520702255614480389250160811898, 101199388044301804167035198499446336399419451, 86918369741985767628242106496018767545685968221295

Offset: 2

Author

N. J. A. Sloane, Feb 14 2013

Keywords

• nonn

Links

• Andrew Howroyd, Table of n, a(n) for n = 2..24
• Peter Tittmann, Enumeration in graphs: counting Hamiltonian cycles [Archived link]
• Robert Israel, The 54 solutions for n=4

Crossrefs

Cf. A222202, A222204.