A233343 Number of tilings of a 7 X 3n rectangle using 7n trominoes of any shape.

1, 441, 614581, 1064557805, 1949314526229, 3619365754064658, 6743148875847013949, 12573396789552627635974, 23449283563696481324707977, 43734844458505039459034141789, 81570040233489554572733439665568, 152137050633841639720340771054558899

Offset

0,2

Links

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

Wikipedia, Tromino

Crossrefs

Trisection of column k=7 of A233320.

Sequence in context: A264277 A268874 A264223 * A110996 A013769 A013899

Adjacent sequences: A233340 A233341 A233342 * A233344 A233345 A233346

Keyword

nonn

Author

Alois P. Heinz, Dec 07 2013

Status

approved