OFFSET
0,3
EXAMPLE
a(3) = 14, because there are 14 tilings of a 3 X 3 square using dominoes and straight (3 X 1) trominoes:
._____. ._____. ._____. ._____. .___._. .___._. .___._.
| | | | | | | | | |___| | |___| | | | | |___| | |___| |
| | | | | |_|_| | |___| | | | | |_|_| | |___| | | | | |
|_|_|_| |_|___| |_|___| |_|_|_| |___|_| |___|_| |_|_|_|
._____. ._____. ._____. ._____. ._____. ._____. ._____.
|_____| |_____| |_____| |_____| | |___| | | | | |___| |
|_____| | |___| | | | | |___| | |_|___| |_|_|_| |___|_|
|_____| |_|___| |_|_|_| |___|_| |_____| |_____| |_____| .
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Alois P. Heinz, Nov 30 2012
EXTENSIONS
a(12) from Alois P. Heinz, Sep 30 2014
STATUS
approved