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A219874 Number of tilings of an n X n square using dominoes and straight (3 X 1) trominoes. 5
1, 0, 2, 14, 184, 9612, 1143834, 354859954, 295743829064, 631206895803116, 3541054185616706122, 51821077154605344550820, 1976225122734369352127065686 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
LINKS
EXAMPLE
a(3) = 14, because there are 14 tilings of a 3 X 3 square using dominoes and straight (3 X 1) trominoes:
._____. ._____. ._____. ._____. .___._. .___._. .___._.
| | | | | | | | | |___| | |___| | | | | |___| | |___| |
| | | | | |_|_| | |___| | | | | |_|_| | |___| | | | | |
|_|_|_| |_|___| |_|___| |_|_|_| |___|_| |___|_| |_|_|_|
._____. ._____. ._____. ._____. ._____. ._____. ._____.
|_____| |_____| |_____| |_____| | |___| | | | | |___| |
|_____| | |___| | | | | |___| | |_|___| |_|_|_| |___|_|
|_____| |_|___| |_|_|_| |___|_| |_____| |_____| |_____| .
CROSSREFS
Main diagonal of A219866.
Sequence in context: A191236 A217905 A237852 * A074655 A268005 A158102
KEYWORD
nonn,more
AUTHOR
Alois P. Heinz, Nov 30 2012
EXTENSIONS
a(12) from Alois P. Heinz, Sep 30 2014
STATUS
approved

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Last modified February 22 16:01 EST 2024. Contains 370256 sequences. (Running on oeis4.)