A251073 Number of tilings of a 9 X n rectangle using 3n trominoes of shape I.

1, 1, 1, 19, 57, 121, 783, 2861, 8133, 37160, 143419, 468816, 1876855, 7263468, 25496863, 97187247, 372086645, 1352780401, 5071962134, 19220628318, 71025008365, 265095817718, 997839772024, 3713274525679, 13851695644227, 51940567251136, 193830054345968

Offset

0,4

Links

Alois P. Heinz, Table of n, a(n) for n = 0..1000

Alois P. Heinz, G.f. and Maple program for A251073

Wikipedia, Tromino

Formula

G.f.: see link above.

Maple

# see link above.

Crossrefs

Column k=3 of A251072.

Cf. A236577.

Sequence in context: A367518 A093362 A341176 * A176413 A263336 A061973

Adjacent sequences: A251070 A251071 A251072 * A251074 A251075 A251076

Keyword

nonn

Author

Alois P. Heinz, Nov 29 2014

Status

approved