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A220126
Number of tilings of a 9 X n rectangle using integer-sided rectangular tiles of area 9.
2
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
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
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Dec 06 2012
STATUS
approved