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A351322
Number T(n,k) of tilings of a 3k X n rectangle with right trominoes.
20
1, 1, 1, 1, 0, 1, 1, 0, 2, 1, 1, 0, 4, 0, 1, 1, 0, 8, 8, 4, 1, 1, 0, 16, 0, 18, 0, 1, 1, 0, 32, 64, 88, 72, 8, 1, 1, 0, 64, 0, 468, 384, 162, 0, 1, 1, 0, 128, 512, 2672, 8544, 4312, 520, 16, 1, 1, 0, 256, 0, 16072, 76800, 118586, 22656, 1514, 0, 1, 1, 0, 512, 4096, 100064, 1168512, 3403624, 1795360, 204184, 4312, 32, 1
OFFSET
0,9
COMMENTS
The table is read by descending antidiagonals.
If read by columns or rows:
T(n,1) = A077957(n+1)
T(2,k) = A000079(k) = 2^k
T(4,k) = A046984(k)
T(5,k) = A084478(k)
T(n,2) = A351323(n)
T(7,k) = A351324(k)
Linear recurrences with different numbers of parameters are known for the sequences above.
Overview:
Constant Number of
side length Sequence parameters
2 T(2,k) 1
3 T(n,1),T(3,k) 2
4 T(4,k) 3 see A046984
5 T(5,k) 4 see A084478
6 T(n,2),T(6,k) 11 see A351323
7 T(7,k) 17 see A351324
8 T(8,k) >30
9 T(n,3),T(9,k) >30
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..495 (first 31 antidiagonals).
Gerhard Kirchner, Tiling algorithm
Gerhard Kirchner, Maxima Code
Gerhard Kirchner, More sequences
Cristopher Moore, Some Polyomino Tilings of the Plane, arXiv:math/9905012 [math.CO], 1999.
EXAMPLE
6 X 2 rectangle: 4 tilings
___ ___ ___ ___
| _| | _| |_ | |_ |
|_| | |_| | | |_| | |_|
|___| |___| |___| |___|
| _| |_ | | _| |_ |
|_| | | |_| |_| | | |_|
|___| |___| |___| |___|
.
Table T(n,k) begins:
n\k__0__1______2_________3_____________4
0: 1 1 1 1 1
1: 1 0 0 0 0
2: 1 2 4 8 16
3: 1 0 8 0 64
4: 1 4 18 88 468
5: 1 0 72 384 8544
6: 1 8 162 4312 118586
7: 1 0 520 22656 1795360
8: 1 16 1514 204184 29986082
9: 1 0 4312 1193600 467966840
10: 1 32 13242 9567192 7758809670
11: 1 0 39088 63112256 124693887784
PROG
(Maxima) See Maxima Code link.
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Gerhard Kirchner, Feb 21 2022
STATUS
approved