A219872 Number of tilings of a 9 X n rectangle using dominoes and straight (3 X 1) trominoes.

1, 5, 249, 17395, 862953, 53074167, 3105936858, 181382499259, 10750194262698, 631206895803116, 37197513508819191, 2191568660367709311, 129026759279686110418, 7600920859497795763717, 447657086066162084823497, 26365510156948695071183306

Offset

0,2

Links

Alois P. Heinz, Table of n, a(n) for n = 0..75

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

Adjacent sequences: A219869 A219870 A219871 * A219873 A219874 A219875

Keyword

nonn

Author

Alois P. Heinz, Nov 30 2012

Status

approved