A362299
Number of tilings of a 3 X 2n rectangle using dominos and 2 X 2 right triangles.
Original entry on oeis.org
1, 7, 55, 445, 3625, 29575, 241375, 1970125, 16080625, 131254375, 1071334375, 8744528125, 71375265625, 582584734375, 4755218359375, 38813412578125, 316805850390625, 2585857315234375, 21106485396484375, 172276994236328125, 1406172661416015625
Offset: 0
a(1)=7:
___ _ _ ___ ___ _ _ ___ ___ _ _ ___ ___ _
| /| | | | /| |\ | | | |\ | |___| | | |___| | | | |
|/__|_| |_|/__| |__\|_| |_|__\| |___|_| |_|___| |_|_|_|
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LinearRecurrence[{10, -15}, {1, 7}, 30] (* Paolo Xausa, Jul 20 2024 *)
A353879
Number of tilings of a 4 X n rectangle using right trominoes, dominoes and 1 X 1 tiles.
Original entry on oeis.org
1, 5, 189, 3633, 83374, 1817897, 40220893, 886130549, 19546906987, 431024540644, 9505433227293, 209617856008535, 4622624792880217, 101940750143038657, 2248057208102711472, 49575464007447758483, 1093267021618939507743, 24109360928450426884813, 531673668551361276666101
Offset: 0
a(2)=189.
The number of tilings (mirroring included) using r trominoes
___ ___ ___ ___
r=1: | _| | _| | |_| |_2_| r=0: 71 = A030186(4)
|_|_| |_| | |___| |_ |
| 7 | |3|_| | 7 | |3|_|
|___| |___| |___| |___|
4*7 + 4*3 + 4*7 + 4*6 = 92
___ ___ ___ ___ ___ ___ ___
r=2: | _| | _| | _| | _| | _| | |_| | |_|
|_| | |_|2| |_|_| |_|_| |_|_| |___| |___|
|___| | |_| | _|_|_| | |_ | |_ | | _|
|_2_| |___| |_|_| |___| |_|_| |_|_| |_|_|
4*2 + 2*2 + 4*1 + 2*1 + 4*1 + 2*1 + 2*1 = 26
Result: a(2) = 71+92+26 = 189.
Legend:
___ ___ ___
|_2_| stands for |___| or |_|_|
_ _ _ _
_|3| _| | _|_| _|_|
|___| stands for |_|_| or |___| or |_|_|
___ ___ ___ ___ ___ ___ ___ ___
| 7 | |___| |_|_| |___| | | | |_| | | |_| |_|_|
|___| stands for |___|,|___|,|_|_|,|_|_|,|_|_|,|_|_| or |_|_|
A353965
Number of tilings of a 3 X n rectangle using 2 X 2 and 1 X 1 tiles and right trominoes.
Original entry on oeis.org
1, 1, 13, 47, 259, 1189, 5877, 28167, 136723, 660173, 3194613, 15445007, 74699811, 361230229, 1746933205, 8448061879, 40854753875, 197572345789, 955455626773, 4620559362303, 22344915889827, 108059470995013, 522573007884725, 2527150465444071, 12221238828079379
Offset: 0
a(2) = 13:
v h,v h=v h,v
___ ___ ___ ___ ___
| | | |_| | _| | _| |_|_| mirroring included
|___| |___| |_| | |_|_| |_|_| h: horizontal, v: vertical
|_|_| |_|_| |___| |_|_| |_|_|
2 + 4 + 2 + 4 + 1 = 13
A354011
Number of tilings of a 3 X n rectangle using 2 X 2 tiles, right trominoes and dominoes.
Original entry on oeis.org
1, 0, 7, 8, 81, 184, 1051, 3176, 14609, 50408, 210903, 773888, 3102369, 11711856, 46045259, 176114128, 686258465, 2640610128, 10247733223, 39540368248, 153162778865, 591718044968, 2290106238779, 8852558325048, 34248315785777, 132424316290104, 512224146701367
Offset: 0
a(2)=7:
___ ___ ___ ___ ___ ___ ___
| | |___| |_ | | _| |___| |___| |_|_|
|___| | | | |_| |_| | |___| |_|_| |_|_|
|___| |___| |___| |___| |___| |_|_| |___|
A354012
Number of tilings of a 4 X n rectangle using 2 X 2 tiles, right trominoes and dominoes.
Original entry on oeis.org
1, 1, 17, 81, 702, 4623, 35044, 248045, 1819731, 13110984, 95362462, 690253391, 5008926698, 36300216768, 263252448712, 1908449014617, 13837881924141, 100326715619679, 727420462629671, 5274035027493046, 38238994112367061, 277246970248002472, 2010151423463689959
Offset: 0
a(2)=17, mirroring included (h: horizontal, v: vertical):
v v h,v v h
___ ___ ___ ___ ___ ___ ___ ___ ___ ___
| | | | | | |___| |___| | | | |___| |___| |___| | _|
|___| |___| |___| |_ | |___| |_|_| | | | |___| | | |_| |
|___| | | | | | | |_| |___| | | | |_|_| | | | |___| | |_|
|___| |_|_| |___| |___| |___| |_|_| |___| |_|_| |___| |___|
2 + 2 + 1 + 4 + 1 + 1 + 1 + 2 + 1 + 2 = 17.
- Index entries for linear recurrences with constant coefficients, signature (5,28,-69,-142,194,78,-57,-36,70,-32).
A354130
Triangle read by rows: T(k,n) (k >= 0, n = 0, ..., k) = number of tilings of a k X n rectangle using 2 X 2, and 1 X 1 tiles, right trominoes and dominoes.
Original entry on oeis.org
1, 1, 1, 1, 2, 12, 1, 3, 48, 405, 1, 5, 216, 4185, 103300, 1, 8, 936, 40320, 2352830, 124098498, 1, 13, 4104, 397755, 55004286, 6763987198, 863829618636, 1, 21, 17928, 3892293, 1274945897, 364713815832, 108969107997657, 32100965172272499
Offset: 0
Triangle begins
k\n_0__1____2______3________4__________5____________6
0: 1
1: 1 1
2: 1 2 12
3: 1 3 48 405
4: 1 5 216 4185 103300
5: 1 8 936 40320 2352830 124098498
6: 1 13 4104 397755 55004286 6763987198 863829618636
A354131
Number of tilings of a 2 X n rectangle using 2 X 2 and 1 X 1 tiles, right trominoes and dominoes.
Original entry on oeis.org
1, 2, 12, 48, 216, 936, 4104, 17928, 78408, 342792, 1498824, 6553224, 28652616, 125277192, 547747272, 2394904968, 10471198536, 45783025416, 200176267464, 875226954888, 3826738469448, 16731577137672, 73155162229704, 319854949515144, 1398495821923656
Offset: 0
a(3)=48
Number of tilings without a 2 X 2 square: 44, see A353878.
Number of other tilings: 4
___ _ ___ _ _ ___ _ ___
| | | | |_| | | | |_| |
|___|_| |___|_| |_|___| |_|___|
A354132
Number of tilings of a 3 X n rectangle using 2 X 2 and 1 X 1 tiles, right trominoes and dominoes.
Original entry on oeis.org
1, 3, 48, 405, 4185, 40320, 397755, 3892293, 38193444, 374425263, 3671810235, 36003770640, 353046480345, 3461866214283, 33946152068808, 332866572321933, 3263999126947497, 32005882711563552, 313840950402409011, 3077438640586986141, 30176522977460549436
Offset: 0
a(2) = 48, see 2 X 3, A354131.
A362298
Number of tilings of a 4 X n rectangle using dominos and 2 X 2 right triangles.
Original entry on oeis.org
1, 1, 19, 55, 472, 2023, 13249, 66325, 392299, 2088856, 11877025, 64803157, 362823607, 1998759703, 11123273896, 61509329983, 341492705365, 1891193243713, 10489893539203, 58127214942544, 322296397820593, 1786338231961609, 9903234373856059, 54893955008138983
Offset: 0
a(2) = 19.
Partitions of a 2 X 2 square (triangles or dominos):
___ ___ ___ ___
| /| |\ | |___| | | |
|/__| |__\| |___| |_|_|
2t 2d
___ ___ ___ ___ ___ ___ _ ___ _ _______
|2t |2t | |2t |2d | |2d |2t | | |2t | | |only d |
|___|___| |___|___| |___|___| |_|___|_| |_______|
4 ways + 4 ways + 4 ways + 2 ways + 5 ways = 19 ways
Only dominos: A005178(3) = 5.
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LinearRecurrence[{4,18,-48,-42,99},{1,1,19,55,472},24] (* Stefano Spezia, Apr 20 2023 *)
Comments