A219869 Number of tilings of a 6 X n rectangle using dominoes and straight (3 X 1) trominoes.

1, 2, 30, 472, 5624, 82634, 1143834, 15859323, 223026907, 3105936858, 43427618185, 606962113407, 8477372675760, 118475405895601, 1655302050975409, 23128348583334118, 323168394713538001, 4515400902297318144, 63091618970759626487, 881547198837947075202

Offset

0,2

Links

Alois P. Heinz, Table of n, a(n) for n = 0..300

Example

a(1) = 2, because there are 2 tilings of a 6 X 1 rectangle using dominoes and straight (3 X 1) trominoes:
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Crossrefs

Column k=6 of A219866.

Sequence in context: A296980 A219706 A318477 * A072976 A143414 A099046

Adjacent sequences: A219866 A219867 A219868 * A219870 A219871 A219872

Keyword

nonn

Author

Alois P. Heinz, Nov 30 2012

Status

approved