login
A192092
Number of tatami tilings of a 6 X n grid (with monomers allowed).
2
1, 13, 156, 196, 238, 325, 450, 827, 1404, 2828, 4603, 7890, 12475, 20396, 34708, 57979, 102658, 170075, 292948, 482036, 812571, 1365010, 2293755, 3918292, 6555468, 11171195, 18648162, 31563547, 53005132, 89383740, 151102715
OFFSET
0,2
COMMENTS
A tatami tiling consists of dimers (1 X 2) and monomers (1 X 1) where no four meet at a point.
LINKS
A. Erickson, F. Ruskey, M. Schurch and J. Woodcock, Monomer-Dimer Tatami Tilings of Rectangular Regions, Electronic Journal of Combinatorics, 18(1) (2011) P109, 24 pages.
EXAMPLE
Here are some tatami tilings of the 6 X 3 grid:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
|_ _| |_| |_| |_| |_|_ _| | | |_ _| |_| | |_| | |_ _| |
|_ _|_| |_| | | |_|_ _| |_| |_| |_|_| |_| | |_|_| | |_|
|_|_ _|_|_|_| |_|_ _|_|_|_| |_|_|_ _|_|_| |_|_ _|_|_|_|
CROSSREFS
Sequence in context: A204766 A163415 A077416 * A297454 A102146 A162768
KEYWORD
nonn
AUTHOR
Frank Ruskey and Yuji Yamauchi (eugene.uti(AT)gmail.com), Jul 14 2011
STATUS
approved