A219949 Number of tilings of an 8 X n rectangle using right trominoes and 2 X 2 tiles.

1, 0, 13, 16, 245, 1128, 10534, 71248, 652036, 5141408, 45081311, 377481816, 3256166909, 27751269104, 238314397799, 2040642918208, 17506339185192, 150079258587200, 1287249575901534, 11038702753296720, 94675989650833007, 811957493293460552, 6963826351562090734

Offset

0,3

Links

Alois P. Heinz, Table of n, a(n) for n = 0..300

Example

a(2) = 13, because there are 13 tilings of an 8 X 2 rectangle using right trominoes and 2 X 2 tiles:
.___.  .___.  .___.  .___.  .___.  .___.
| ._|  | ._|  |_. |  |_. |  | ._|  | ._|
|_| |  |_| |  | |_|  | |_|  |_| |  |_| |
|___|  |___|  |___|  |___|  |___|  |___|
| ._|  |_. |  | ._|  |_. |  | . |  | . |
|_| |  | |_|  |_| |  | |_|  |___|  |___|
|___|  |___|  |___|  |___|  | ._|  |_. |
| . |  | . |  | . |  | . |  |_| |  | |_|
|___|  |___|  |___|  |___|  |___|  |___|
.___.  .___.  .___.  .___.  .___.  .___.  .___.
|_. |  |_. |  | . |  | . |  | . |  | . |  | . |
| |_|  | |_|  |___|  |___|  |___|  |___|  |___|
|___|  |___|  | ._|  | ._|  |_. |  |_. |  | . |
| . |  | . |  |_| |  |_| |  | |_|  | |_|  |___|
|___|  |___|  |___|  |___|  |___|  |___|  | . |
| ._|  |_. |  | ._|  |_. |  | ._|  |_. |  |___|
|_| |  | |_|  |_| |  | |_|  |_| |  | |_|  | . |
|___|  |___|  |___|  |___|  |___|  |___|  |___|

Crossrefs

Column k=8 of A219946.

Sequence in context: A217179 A107081 A029526 * A173632 A061060 A084307

Adjacent sequences: A219946 A219947 A219948 * A219950 A219951 A219952

Keyword

nonn

Author

Alois P. Heinz, Dec 01 2012

Status

approved