A220126 Number of tilings of a 9 X n rectangle using integer-sided rectangular tiles of area 9.

1, 1, 1, 2, 3, 4, 6, 9, 13, 37, 64, 95, 188, 326, 513, 875, 1449, 2302, 4289, 7422, 12072, 21561, 37559, 62571, 107806, 184027, 306628, 532661, 915705, 1537768, 2654311, 4574383, 7752577, 13292546, 22778306, 38625110, 66213867, 113475693, 192821642, 330086669

Offset

0,4

Links

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

Example

a(5) = 4, because there are 4 tilings of a 9 X 5 rectangle using integer-sided rectangular tiles of area 9:
._._._._._.  ._____._._.  ._._____._.  ._._._____.
| | | | | |  |     | | |  | |     | |  | | |     |
| | | | | |  |     | | |  | |     | |  | | |     |
| | | | | |  |_____| | |  | |_____| |  | | |_____|
| | | | | |  |     | | |  | |     | |  | | |     |
| | | | | |  |     | | |  | |     | |  | | |     |
| | | | | |  |_____| | |  | |_____| |  | | |_____|
| | | | | |  |     | | |  | |     | |  | | |     |
| | | | | |  |     | | |  | |     | |  | | |     |
|_|_|_|_|_|  |_____|_|_|  |_|_____|_|  |_|_|_____|

Crossrefs

Column k=9 of A220122.

Sequence in context: A022859 A352039 A318728 * A328071 A039884 A240496

Adjacent sequences: A220123 A220124 A220125 * A220127 A220128 A220129

Keyword

nonn

Author

Alois P. Heinz, Dec 06 2012

Status

approved