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A219872
Number of tilings of a 9 X n rectangle using dominoes and straight (3 X 1) trominoes.
2
1, 5, 249, 17395, 862953, 53074167, 3105936858, 181382499259, 10750194262698, 631206895803116, 37197513508819191, 2191568660367709311, 129026759279686110418, 7600920859497795763717, 447657086066162084823497, 26365510156948695071183306
OFFSET
0,2
LINKS
EXAMPLE
a(1) = 5, because there are 5 tilings of a 9 X 1 rectangle using dominoes and straight (3 X 1) trominoes:
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CROSSREFS
Column k=9 of A219866.
Sequence in context: A125533 A068727 A135095 * A282734 A115739 A142202
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Nov 30 2012
STATUS
approved