A192092 Number of tatami tilings of a 6 X n grid (with monomers allowed).

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

Table of n, a(n) for n=0..30.

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

Cf. A192091, A192093.

Sequence in context: A204766 A163415 A077416 * A297454 A102146 A162768

Adjacent sequences: A192089 A192090 A192091 * A192093 A192094 A192095

Keyword

nonn

Author

Frank Ruskey and Yuji Yamauchi (eugene.uti(AT)gmail.com), Jul 14 2011

Status

approved