cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-10 of 15 results. Next

A353877 Triangle read by rows: T(n,k) = number of tilings of a n X k rectangle using right trominoes, dominoes and 1 X 1 tiles, n >= 0, k = 0..n.

Original entry on oeis.org

1, 1, 1, 1, 2, 11, 1, 3, 44, 369, 1, 5, 189, 3633, 83374, 1, 8, 798, 34002, 1817897, 90916452, 1, 13, 3383, 323293, 40220893, 4635661331, 546063639624, 1, 21, 14328, 3058623, 886130549, 235025597912, 63919977468729, 17259079054003609, 1, 34, 60697, 28982628, 19546906987, 11935601703140, 7495901454256347, 4669873251135795702, 2916019543694306398589
Offset: 0

Views

Author

Gerhard Kirchner, May 09 2022

Keywords

Comments

Tiling algorithm, see A351322.
Reading the sequence {T(n,k)} for k>n, use T(k,n) instead of T(n,k).

Examples

			Triangle begins
n\k_0__1____2______3________4__________5____________6
0:  1
1:  1  1
2:  1  2   11
3:  1  3   44    369
4:  1  5  189   3633    83374
5:  1  8  798  34002  1817897   90916452
6:  1 13 3383 323293 40220893 4635661331 546063639624
		

Crossrefs

Row/columns 0..4 are A000012, A000045(n+1), A110679, A353878, A353879.
Main diagonal is A353934.

Programs

A353963 Triangle read by rows: T(n,k) = number of tilings of a n X k rectangle using 2 X 2 and 1 X 1 tiles and right trominoes, n >= 0, k=0..n.

Original entry on oeis.org

1, 1, 1, 1, 1, 6, 1, 1, 13, 47, 1, 1, 45, 259, 3376, 1, 1, 122, 1189, 29683, 475962, 1, 1, 373, 5877, 311894, 9250945, 355724934, 1, 1, 1073, 28167, 3015423, 164776003, 12126673297, 777719132265, 1, 1, 3182, 136723, 30295051, 3051272172, 436744432876, 53090133270415, 6953251175836902
Offset: 0

Views

Author

Gerhard Kirchner, May 13 2022

Keywords

Comments

For tiling algorithm, see A351322.
Reading the sequence {T(n,k)} for k>n, use T(k,n) instead of T(n,k).

Examples

			Triangle begins
  n\k  0 1   2    3      4       5         6
  ------------------------------------------
  0:   1
  1:   1 1
  2:   1 1   6
  3:   1 1  13   47
  4:   1 1  45  259   3376
  5:   1 1 122 1189  29683  475962
  6:   1 1 373 5877 311894 9250945 355724934
		

Crossrefs

Row/columns 0..3 are A000012, A000012, A353964, A353965.
Main diagonal is A354067.

Programs

A353777 Number of tilings of an n X n square using dominoes, monominoes and 2 X 2 tiles.

Original entry on oeis.org

1, 1, 8, 163, 15623, 5684228, 8459468955, 50280716999785, 1202536689448371122, 115462301811597894998929, 44537596159273736617786474211, 69003082378039459280864860681919942, 429429579883061866326542598342441907826951, 10734684843612889640707750537898705644071715970757
Offset: 0

Views

Author

Alois P. Heinz, May 07 2022

Keywords

Examples

			a(2) = 8:
  .___.  .___.  .___.  .___.  .___.  .___.  .___.  .___.
  |   |  |_|_|  |___|  | | |  |_|_|  |___|  |_| |  | |_|
  |___|  |_|_|  |___|  |_|_|  |___|  |_|_|  |_|_|  |_|_| .
		

Crossrefs

Formula

a(n) = A352589(n,n).

A353878 Number of tilings of a 3 X n rectangle using right trominoes, dominoes and 1 X 1 tiles.

Original entry on oeis.org

1, 3, 44, 369, 3633, 34002, 323293, 3058623, 28982628, 274494621, 2600148629, 24628666626, 233286962601, 2209723174731, 20930806288252, 198259418947833, 1877940242218857, 17788105074906162, 168491350295593637, 1595972975308532199, 15117273008425964916
Offset: 0

Views

Author

Gerhard Kirchner, May 09 2022

Keywords

Comments

Tiling algorithm see A351322.

Examples

			a(2)=44
The number of tilings (mirroring included) using r trominoes
      ___   ___        ___
r=1: |  _| | |_| r=2: |  _| r=0: 22 = A030186(3)
     |_|3| |___|      |_| |
     |___| |_2_|      |___|
      4*3 + 4*2   +    2*1   +   22 = 44
Legend:
   ___              ___      ___
  |_2_| stands for |___| or |_|_|
     _                _        _        _
   _|3|             _| |     _|_|     _|_|
  |___| stands for |_|_| or |___| or |_|_|
		

Crossrefs

Programs

Formula

G.f.: (1-3*x-7*x^2+3*x^3-2*x^4) / (1-6*x-33*x^2-3*x^3+40*x^4-15*x^5).
a(n) = 6*a(n-1) + 33*a(n-2) + 3*a(n-3) - 40*a(n-4) + 15*a(n-5).

A353964 Number of tilings of a 2 X n rectangle using 2 X 2 and 1 X 1 tiles and right trominoes.

Original entry on oeis.org

1, 1, 6, 13, 45, 122, 373, 1073, 3182, 9293, 27349, 80178, 235509, 691097, 2028998, 5955501, 17482685, 51318186, 150642613, 442198913, 1298048350, 3810328141, 11184967717, 32832705122, 96378199989, 282911661033, 830468071222, 2437782776365, 7155946454541
Offset: 0

Views

Author

Gerhard Kirchner, May 13 2022

Keywords

Comments

For tiling algorithm see A351322.

Examples

			a(3)=13, see example 3 X 2, A353965.
		

Crossrefs

Programs

Formula

G.f.: 1 / (1 - x - 5*x^2 - 2*x^3).
a(n) = a(n-1) + 5*a(n-2) + 2*a(n-3).

A354010 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 tiles, right trominoes and dominoes.

Original entry on oeis.org

1, 1, 0, 1, 1, 3, 1, 0, 7, 8, 1, 1, 17, 81, 702, 1, 0, 41, 184, 4623, 41952, 1, 1, 99, 1051, 35044, 654673, 16600824, 1, 0, 239, 3176, 248045, 7407376, 358635313, 13298557992, 1, 1, 577, 14609, 1819731, 100694199, 8448412164, 569631442289, 43157780553934
Offset: 0

Views

Author

Gerhard Kirchner, May 14 2022

Keywords

Comments

For tiling algorithm, see A351322.
Reading the sequence {T(k,n)}, use T(n,k) instead of T(k,n) for n>k.
T(1,n) = A000035(n+1) = (n+1) mod 2,
T(2,n) = A001333(n), T(3,n) = A354011(n), T(4,n) = A354012(n).

Examples

			Triangle begins
  k\n 0 1   2    3      4       5         6
  -----------------------------------------
  0   1
  1   1 0
  2   1 1   3
  3   1 0   7    8
  4   1 1  17   81    702
  5   1 0  41  184   4623   41952
  6   1 1  99 1051  35044  654673  16600824
		

Crossrefs

Programs

A352590 Number of tilings of a 4 X n rectangle using 2 X 2 and 1 X 1 tiles and dominoes.

Original entry on oeis.org

1, 5, 90, 1125, 15623, 210690, 2865581, 38879777, 527889422, 7165926641, 97281018915, 1320614646178, 17927775213129, 243375024977525, 3303891838175262, 44851355548842869, 608871075513683799, 8265613771134660506, 112208272012556064101, 1523262112532452904985
Offset: 0

Views

Author

Gerhard Kirchner, Mar 22 2022

Keywords

Comments

The sequence is based on A352589.

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[(1-6x-15x^2+74x^3-18x^4-122x^5+64x^6+48x^7-24x^8)/(1-11x-50x^2+189x^3+289x^4-1164x^5+408x^6+1010x^7-576x^8-216x^9+120x^10),{x,0,20}],x] (* or *) LinearRecurrence[{11,50,-189,-289,1164,-408,-1010,576,216,-120},{1,5,90,1125,15623,210690,2865581,38879777,527889422,7165926641},30] (* Harvey P. Dale, Feb 27 2023 *)

Formula

G.f.: (1-6*x-15*x^2+74*x^3-18*x^4-122*x^5+64*x^6+48*x^7-24*x^8) / (1-11*x-50*x^2+189*x^3+289*x^4-1164*x^5+408*x^6+1010*x^7-576*x^8-216*x^9+120*x^10).
Recurrence: a(n)=11*a(n-1) + 50*a(n-2) - 189*a(n-3) - 289*a(n-4) + 1164*a(n-5) - 408*a(n-6) - 1010*a(n-7) + 576*a(n-8) + 216*a(n-9) - 120*a(n-10).

A352591 Number of tilings of a 5 X n rectangle using 2 X 2 and 1 X 1 tiles and dominoes.

Original entry on oeis.org

1, 8, 306, 7546, 210690, 5684228, 154869092, 4207660108, 114411435032, 3110251075956, 84557403666284, 2298788023809188, 62495515282157930, 1699018055917569318, 46189937030173640586, 1255731173553810109440, 34138623221740999081824, 928101175618008434398704
Offset: 0

Views

Author

Gerhard Kirchner, Mar 22 2022

Keywords

Comments

The sequence is based on A352589.

Crossrefs

Formula

G.f.: (1 - 7*x - 175*x^2 + 268*x^3 + 5817*x^4 - 8527*x^5 - 62465*x^6 + 86808*x^7 + 299229*x^8 - 339035*x^9 - 761445*x^10 + 575980*x^11 + 1035378*x^12 - 409804*x^13 - 662520*x^14 + 131472*x^15 + 184320*x^16 - 16704*x^17 - 17280*x^18) / (1 - 15*x - 361*x^2 + 200*x^3 + 17183*x^4 - 6963*x^5 - 320541*x^6 + 363476*x^7 + 2096695*x^8 - 2659007*x^9 - 6914929*x^10 + 7710612*x^11 + 13172634*x^12 - 10195340*x^13 - 14247416*x^14 + 5770992*x^15 + 7493472*x^16 - 1420800*x^17 - 1734912*x^18 + 133632*x^19 + 138240*x^20).
Recurrence: a(n) = 15*a(n-1) + 361*a(n-2) - 200*a(n-3) - 17183*a(n-4) + 6963*a(n-5) + 320541*a(n-6) - 363476*a(n-7) - 2096695*a(n-8) + 2659007*a(n-9) + 6914929*a(n-10) - 7710612*a(n-11) - 13172634*a(n-12) + 10195340*a(n-13) + 14247416*a(n-14) - 5770992*a(n-15) - 7493472*a(n-16) + 1420800*a(n-17) + 1734912*a(n-18) - 133632*a(n-19) - 138240*a(n-20).

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

Views

Author

Gerhard Kirchner, May 09 2022

Keywords

Comments

For tiling algorithm see A351322.

Examples

			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 |_|_|
		

Crossrefs

Programs

Formula

G.f.: (1 - 9*x - 64*x^2 + 109*x^3 + 39*x^4 + 41*x^5 + 12*x^6 - 7*x^7 - 2*x^8) / (1 - 14*x - 183*x^2 + 37*x^3 + 1929*x^4 - 2419*x^5 + 212*x^6 + 333*x^7 - 25*x^8-15*x^9).
a(n) = 14*a(n-1) + 183*a(n-2) - 37*a(n-3) - 1929*a(n-4) + 2419*a(n-5) - 212*a(n-6) - 333*a(n-7) + 25*a(n-8) + 15*a(n-9).

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

Views

Author

Gerhard Kirchner, May 13 2022

Keywords

Comments

For tiling algorithm see A351322.

Examples

			a(2) = 13:
    v    h,v   h=v   h,v
   ___   ___   ___   ___   ___
  |   | | |_| |  _| |  _| |_|_|    mirroring included
  |___| |___| |_| | |_|_| |_|_|    h: horizontal, v: vertical
  |_|_| |_|_| |___| |_|_| |_|_|
    2  +  4  +  2  +  4  +  1 = 13
		

Crossrefs

Programs

Formula

G.f.: (1 - 2*x + x^2) / (1 - 3*x - 9*x^2 + x^3 - 2*x^4).
a(n) = 3*a(n-1) + 9*a(n-2) - a(n-3) + 2*a(n-4).
31*a(n) = 18*(-2)^n +13*A200739(n+3) +2*A200739(n+2) +9*A200739(n+1). - R. J. Mathar, Jun 07 2025
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