A220124 Number of tilings of a 6 X n rectangle using integer-sided rectangular tiles of area 6.

1, 1, 2, 4, 7, 13, 46, 88, 209, 473, 1002, 2120, 5197, 11085, 25384, 57234, 126959, 279883, 640387, 1412460, 3182794, 7138463, 15963680, 35593612, 80143244, 178644947, 400681480, 897313564, 2008904252, 4492651815, 10074017008, 22526314856, 50459193392

Offset

0,3

Links

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

Example

a(4) = 7, because there are 7 tilings of a 6 X 4 rectangle using integer-sided rectangular tiles of area 6:
._._._._. ._._._._. ._._._._. ._._._._. ._._._._. ._._._._. ._._._._.
| | | | | |   | | | | |   | | | | |   | |   |   | |     | | | |     |
| | | | | |   | | | | |   | | | | |   | |   |   | |     | | | |     |
| | | | | |___| | | | |___| | | | |___| |___|___| |_____| | | |_____|
| | | | | |   | | | | |   | | | | |   | |   |   | |     | | | |     |
| | | | | |   | | | | |   | | | | |   | |   |   | |     | | | |     |
|_|_|_|_| |___|_|_| |_|___|_| |_|_|___| |___|___| |_____|_| |_|_____|

Crossrefs

Column k=6 of A220122.

Sequence in context: A102115 A102116 A102117 * A101838 A286371 A030135

Adjacent sequences: A220121 A220122 A220123 * A220125 A220126 A220127

Keyword

nonn

Author

Alois P. Heinz, Dec 05 2012

Status

approved