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A368224
Table read by antidiagonals: T(n,k) is the number of tilings of the n X k grid up to 180-degree rotation by an asymmetric tile.
5
1, 3, 3, 4, 10, 4, 10, 36, 36, 10, 16, 136, 256, 136, 16, 36, 528, 2080, 2080, 528, 36, 64, 2080, 16384, 32896, 16384, 2080, 64, 136, 8256, 131328, 524800, 524800, 131328, 8256, 136, 256, 32896, 1048576, 8390656, 16777216, 8390656, 1048576, 32896, 256
OFFSET
1,2
LINKS
Peter Kagey and William Keehn, Counting tilings of the n X m grid, cylinder, and torus, arXiv: 2311.13072 [math.CO], 2023.
EXAMPLE
Table begins:
n\k| 1 2 3 4 5 6
---+---------------------------------------------
1 | 1 3 4 10 16 36
2 | 3 10 36 136 528 2080
3 | 4 36 256 2080 16384 131328
4 | 10 136 2080 32896 524800 8390656
5 | 16 528 16384 524800 16777216 536887296
6 | 36 2080 131328 8390656 536887296 34359869440
MATHEMATICA
A368224[n_, m_] := 2^(n*m/2 - 1) (2^(n*m/2) + Boole[EvenQ[n*m]])
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Peter Kagey, Dec 18 2023
STATUS
approved