A219873 Number of tilings of a 10 X n rectangle using dominoes and straight (3 X 1) trominoes.

1, 7, 506, 58002, 4631107, 458901955, 43427618185, 4095897476480, 392127322268846, 37197513508819191, 3541054185616706122, 337034306456285944790, 32054951461147041813900, 3050527403495695959369072, 290235791993563362905189432, 27614468898770593799634611889

Offset

0,2

Links

Alois P. Heinz, Table of n, a(n) for n = 0..60

Example

a(1) = 7, because there are 7 tilings of a 10 X 1 rectangle using dominoes and straight (3 X 1) trominoes:
._.    ._.    ._.    ._.    ._.    ._.    ._.
| |    | |    | |    | |    | |    | |    | |
|_|    |_|    |_|    |_|    | |    | |    | |
| |    | |    | |    | |    |_|    |_|    |_|
|_|    |_|    | |    | |    | |    | |    | |
| |    | |    |_|    |_|    |_|    |_|    | |
|_|    | |    | |    | |    | |    | |    |_|
| |    |_|    |_|    | |    |_|    | |    | |
|_|    | |    | |    |_|    | |    |_|    |_|
| |    | |    | |    | |    | |    | |    | |
|_|    |_|    |_|    |_|    |_|    |_|    |_|

Crossrefs

Column k=10 of A219866.

Sequence in context: A122523 A293180 A203472 * A224469 A347907 A320980

Adjacent sequences: A219870 A219871 A219872 * A219874 A219875 A219876

Keyword

nonn

Author

Alois P. Heinz, Nov 30 2012

Status

approved