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A251737
Number of tilings of a 5 X n rectangle using n pentominoes of shapes L, U, I.
3
1, 1, 3, 5, 17, 66, 181, 508, 1283, 3664, 10812, 31171, 88565, 245524, 692416, 1968532, 5609977, 15928174, 44982196, 127190716, 360208608, 1021611491, 2896270245, 8202605953, 23226285083, 65780006703, 186369631872, 528047092459, 1495905404102, 4237308534243
OFFSET
0,3
LINKS
Wikipedia, Pentomino
EXAMPLE
a(4) = 17:
._______. ._______. ._______. ._______.
|_____. | | ._____| | | | | | | | ._| |
| | ._|_| |_| ._. | | | | | | | | | | |
| | |_. | | |_| |_| | | | | | | | | | |
| |___| | |_____| | | | | | | | |_| | |
|___|___| (4) |_______| (2) |_|_|_|_| (1) |_|___|_| (2)
._______. ._______. ._______.
| ._| | | | ._| ._| | ._|_. |
| | | | | | | | | | | | | | |
| | | | | | | | | | | | | | |
|_| | | | |_| |_| | |_| | |_|
|___|_|_| (4) |___|___| (2) |___|___| (2) .
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Dec 07 2014
STATUS
approved