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.

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A359885 Number of 3-dimensional tilings of a 2 X 2 X 3n box using trominos (three 1 X 1 X 1 cubes).

Original entry on oeis.org

1, 44, 2512, 145088, 8383744, 484453376, 27994083328, 1617634967552, 93474855387136, 5401434047381504, 312121261353336832, 18035892123135377408, 1042202005934895529984, 60223526164332403490816, 3480009713100277581611008, 201091971436982107249836032
Offset: 0

Views

Author

Gerhard Kirchner, Jan 20 2023

Keywords

Comments

The first recurrence is derived in A359884, "3d-tilings of a 2 X 2 X n box" as a special case of a more general tiling problem: III, example 5.
The example uses two cross section profiles with two overstanding cubes: C (with a common square) and D (with one common edge).

Examples

			a(1)=44.
t1,t2,t3 is a tromino standing on 1,2,3 cubes respectively.
1) Two t2-tiles generate a C-profile or a D-profile in 4 ways each.
   C,D-profile: 4,2 rotation images, D-profile: 2 ways for each image.
    C-profile                      D-profiles
.     ___                      ___                   ___
.   /__ /|               ___ /__ /|            ___ /__ /|
. /__ /| |___          /__ /|   | |          /__ /|   | |
.|   | |/__ /|        |   | |___| |         |   | |___| |
.|   |/__ /| |        |   |/__ /| |         |   |/__ /  |
.|       | |/         |       | |/          |   |   |  /
.|_______|/           |_______|/            |___|___|/
2) t1+t3 generates a C-profile in 4*2=8 ways.
.     ___
.   /   /|                       ______
. /__ /  |    _______          /_____ /|    _______
.|   |  /   /__     /|        |      | |  /__     /|
.|   | |   |  /__ /  |   or   |    __|/  |  /__ /  |
.|   | |   |_|   |  /         |   | |    |_|   |  /
.|___|/      |___|/           |___|/       |___|/
1,2) There are 12 ways to generate a C-profile. The connection of two C-profiles is a 2 X 2 X 3 cuboid. Starting with a C-profile, there are 4*3*3=36 ways to generate this cuboid.
3) There are 4*2=8 ways to generate the cuboid by starting with a D-profile. Therefore, a(1)=36+8=44.
.     ___
.   /   /|          ___       ___
. /__ /  |    ___ /__ /|    /   /|
.|   |   |  /__ /|   | |  /__ /  |
.|___|/| | |   | |___| | |   |  /
.  |___|/  |   |/__ /| | |   | |    or
.          |       | |/  |   | |
.          |_______|/    |___|/
.   _______
. /______ /|          ___
.|       | |    ___ /__ /|    _______
.|    ___|/   /__ /|   | |  /______ /|
.|   | |     |   | |___| | |       | |
.|___|/      |   |/__ /| | |___    | |
.            |       | |/      |   | |
.            |_______|/        |___|/
		

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{60, -128}, {1, 44}, 20] (* Paolo Xausa, Jun 24 2024 *)
  • Maxima
    /* See A359884. */

Formula

G.f.: (1 - 16*x) / (1 - 60*x + 128*x^2).
a(n) = 44*a(n-1) + 6*e(n-1) where e(n) = 96*a(n-1) + 16*e(n-1) with a(n),e(n) <= 0 for n < =0 except for a(0)=1.
a(n) = 60*a(n-1) - 128*a(n-2) for n >= 2.
E.g.f.: exp(30*x)*cosh(2*sqrt(193)*x) + 7*exp(30*x)*sinh(2*sqrt(193)*x)/sqrt(193). - Stefano Spezia, Jan 21 2023

A360064 Number of 3-dimensional tilings of a 2 X 2 X n box using 1 X 1 X 1 cubes and trominos (L-shaped connection of 3 cubes).

Original entry on oeis.org

1, 5, 89, 1177, 16873, 237977, 3366793, 47599097, 673035625, 9516252633, 134553882441, 1902506043833, 26900227288361, 380352114739609, 5377937177440009, 76040613721296249, 1075165950495479017, 15202163218500810073, 214948926180739194569
Offset: 0

Views

Author

Gerhard Kirchner, Jan 30 2023

Keywords

Comments

Recurrence 1 is derived in A359884, "3d-tilings of a 2 X 2 X n box" as a special case of a more general tiling problem: III, example 8.

Examples

			4 rotations:
   ___ ___     ___ ___
  |   |   |   |   |   | (cross sections)
  |   |___|   |___|___|
  |       |   |   |   |
  |_______|   |___|___| a(1) = 4 + 1 = 5.
		

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{13, 20, -64, 112, 224, -128}, {1, 5, 89, 1177, 16873, 237977}, 25] (* Paolo Xausa, Oct 02 2024 *)

Formula

G.f.: (1 - 8*x + 4*x^2 - 16*x^3) / (1 - 13*x - 20*x^2 + 64*x^3 - 112*x^4 - 224*x^5 + 128*x^6).
Recurrence 1:
a(n) = 5*a(n-1) + 2*b(n-1) + c(n-1) + d(n-1) + e(n-1) + 8*a(n-2) + 4*b(n-2) + c(n-2) + 2*d(n-2),
b(n) = 8*a(n-1) + 4*b(n-1) + 2*c(n-1),
c(n) = 20*a(n-1) + 6*b(n-1) + 4*c(n-1) + 4*d(n-1) + 2*e(n-1),
d(n) = 4*a(n-1), e(n) = 16*a(n-1) + 4*b(n-1),
with a(n), b(n), c(n), d(n), e(n) = 0 for n <= 0 except for a(0)=1.
Recurrence 2:
a(n) = 13*a(n-1) + 20*a(n-2) - 64*a(n-3) + 112*a(n-4) + 224*a(n-5) - 128*a(n-6) for n >= 6. For n < 6, recurrence 1 can be used.

A360065 Number of 3-dimensional tilings of a 2 X 2 X n box using 2 X 1 X 1 dominos and trominos (L-shaped connection of 3 cubes).

Original entry on oeis.org

1, 2, 45, 412, 4705, 50374, 549109, 5955544, 64683649, 702259786, 7625147293, 82791470836, 898931464993, 9760376329678, 105975828745957, 1150659965697328, 12493588746237697, 135652375422278290, 1472880803124594061, 15992184812239930060, 173639288800074705121
Offset: 0

Views

Author

Gerhard Kirchner, Jan 30 2023

Keywords

Comments

Recurrence 1 is derived in A359884, "3d-tilings of a 2 X 2 X n box" as a special case of a more general tiling problem: III, example 9.

Examples

			a(2)=45
1) Two parallel trominos and one domino: There are 3 middle axes of the 2 X 2 cube with 4 rotation images each: 12 images.
       ___             ___         ___ ___
     /__ /|          /   /|      /__ /   /|
   /__ /| |___     /__ /  |    /__ /__ /  |
  |   | |/__ /|   |   |  /    |   |   |  /|
  |   |/__ /| | + |___|/   =  |   |___|/| |
  |       | |/                |       | |/
  |_______|/                  |_______|/
2) Two "linked" trominos and one domino: 12 rotation images and, as there is no symmetry plane, 12 mirror images: 24 images.
       ___                       ___         ___ ___
     /   /|                    /   /|      /   /   /|
   /__ /  |      _______     /__ /  |    /__ /__ /  |
  |   |  /     /__     /|   |   |  /    |   |   |  /|
  |   | |  +  |  /__ /  | + |___|/   =  |   |___|/  |
  |   | |     |_|   |  /                |   |   |  /
  |___|/        |___|/                  |___|___|/
3) Using only dominos: A006253(2)=9 ways, Sum: a(2) = 12 + 24 + 9 = 45.
		

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{7, 42, 6, -81, 27}, {1, 2, 45, 412, 4705}, 25] (* Paolo Xausa, Oct 02 2024 *)

Formula

G.f.: (1 - 5*x - 11*x^2 + 7*x^3) / (1 - 7*x - 42*x^2 - 6*x^3 + 81*x^4 - 27*x^5).
Recurrence 1:
a(n) = 2*a(n-1) + b(n-1) + c(n-1) + 13*a(n-2) + 2*b(n-2) + c(n-2) + 2*d(n-2),
b(n) = 12*a(n-1) + 2*b(n-1) + 2*c(n-1) + e(n-1),
c(n) = 16*a(n-1) + 6*b(n-1) + c(n-1) + 2*e(n-1),
d(n) = 4*a(n-1) + 2*b(n-1) + d(n-1),
e(n) = 16*a(n-1) + 5*b(n-1) + 2*c(n-1) + 2*d(n-1),
with a(n), b(n), c(n), d(n), e(n) = 0 for n <= 0 except for a(0)=1.
Recurrence 2:
a(n) = 7*a(n-1) + 42*a(n-2) + 6*a(n-3) - 81*a(n-4) + 27*a(n-5) for n >= 5.
For n < 5, recurrence 1 can be used.

A359886 Number of 3-dimensional tilings of a 2 X 2 X n box using 2 X 2 X 1 plates and trominos (three 1 X 1 X 1 cubes).

Original entry on oeis.org

1, 1, 3, 49, 231, 789, 4771, 27225, 122799, 607469, 3255979, 16253649, 80098519, 409480005, 2079921395, 10411734921, 52523676351, 266059774429, 1341128940795, 6758479842689, 34138205819239, 172324729379509, 869131661400259, 4386075013348025, 22138673661637327
Offset: 0

Views

Author

Gerhard Kirchner, Jan 20 2023

Keywords

Comments

Recurrence 1 is derived in A359884, "3d-tilings of a 2 X 2 X n box" as a special case of a more general tiling problem: III, example 6.

Examples

			a(3) = 49.
The number of tilings only using plates is A001045(3) = 5.
The number of tilings only using trominos is A359885(1) = 44.
These terms are to be added as, for n=3, there is no tiling using both tiles.
		

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{2, 1, 58, 72, 32, -128}, {1, 1, 3, 49, 231, 789}, 30] (* Paolo Xausa, Jun 24 2024 *)
  • Maxima
    /* See link "Maxima code". */

Formula

G.f.: (1 - x - 16*x^3) / (1 - 2*x - x^2 - 58*x^3 - 72*x^4 - 32*x^5 + 128*x^6).
Recurrence 1:
a(n) = a(n-1) + 3*c(n-2) + 2*a(n-2) + 4*c(n-3) + 8*a(n-3),
c(n) = 12*a(n-1) + c(n-1) + 16*a(n-2) + 16*c(n-3),
with a(n),c(n) <= 0 for n <= 0 except for a(0)=1.
Recurrence 2:
a(n) = 2*a(n-1) + a(n-2) + 58*a(n-3) + 72*a(n-4) + 32*a(n-5) - 128*a(n-6) for n >= 6.
For n < 6, recurrence 1 can be used.

A360066 Number of 3-dimensional tilings of a 2 X 2 X n box using 1 X 1 X 1 cubes, 2 X 1 X 1 dominos and trominos (L-shaped connection of 3 cubes).

Original entry on oeis.org

1, 11, 444, 13311, 422617, 13265660, 417336617, 13123557903, 412719195520, 12979269602143, 408175860119021, 12836425011761592, 403683424226081169, 12695147020245034099, 399240466722076292612, 12555423726269799691295, 394846409914451855949249
Offset: 0

Views

Author

Gerhard Kirchner, Jan 30 2023

Keywords

Comments

Recurrence 1 is derived in A359884, "3d-tilings of a 2 X 2 X n box" as a special case of a more general tiling problem: III, example 10.

Crossrefs

Programs

Formula

G.f.: (1 - 15*x - 18*x^2 - 23*x^3 + 7*x^4) / (1 - 26*x - 176*x^2 + 146*x^3 + 14*x^4 + 140*x^5 - 27*x^6).
Recurrence 1:
a(n) = 11*a(n-1) + 4*b(n-1) + 2*c(n-1) + d(n-1) + e(n-1) + 29*a(n-2) + 6*b(n-2) + c(n-2) + 2*d(n-2),
b(n) = 32*a(n-1) + 9*b(n-1) + 4*c(n-1) + 2*d(n-1) + e(n-1),
c(n) = 52*a(n-1) + 14*b(n-1) + 5*c(n-1) + 4*d(n-1) + 2*e(n-1),
d(n) = 14*a(n-1) + 3*b(n-1) + d(n-1),
e(n) = 48*a(n-1) + 11*b(n-1) + 2*c(n-1) + 2*d(n-1),
with a(n), b(n), c(n), d(n), e(n) = 0 for n <= 0 except for a(0)=1.
Recurrence 2:
a(n) = 26*a(n-1) + 176*a(n-2) - 146*a(n-3) - 14*a(n-4) - 140*a(n-5) + 27*a(n-6) for n >= 6. For n < 6, recurrence 1 can be used.

A360575 Number of 3-dimensional tilings of a 2 X 2 X n box using 1 X 1 X 1 cubes, 2 X 1 X 1 dominos and 2 X 2 X 1 plates.

Original entry on oeis.org

1, 8, 153, 2470, 41571, 693850, 11602579, 193942076, 3242104149, 54196828452, 905988148597, 15145052657186, 253174020910071, 4232212575080006, 70748267813548207, 1182671546039152712, 19770264765434877913, 330491902143708738464
Offset: 0

Views

Author

Gerhard Kirchner, Feb 12 2023

Keywords

Comments

Recurrence 1 is derived in A359884, "3d-tilings of a 2 X 2 X n box" as a special case of a more general tiling problem: III, example 11.

Crossrefs

Formula

G.f.: (1-8*x+4*x^2+11*x^3-6*x^4) / (1-16*x-21*x^2+157*x^3-100*x^4-65*x^5+42*x^6).
Recurrence 1:
a(n) = 8*a(n-1) + 3*b(n-1) + 2*c(n-1) + d(n-1) + e(n-1) + 7*a(n-2)
b(n) = 12*a(n-1) + 5*b(n-1) + 2*c(n-1) + 2*d(n-1) + e(n-1)
c(n) = 16*a(n-1) + 4*b(n-1) + 2*c(n-1)
d(n) = 2*a(n-1) + b(n-1) + d(n-1)
e(n) = 12*a(n-1) + 3*b(n-1)
with a(n),b(n),c(n),d(n),e(n)= 0 for n<=0 except for a(0)=1.
Recurrence 2:
a(n)=16*a(n-1) + 21*a(n-2) - 157*a(n-3) + 100*a(n-4) + 65*a(n-5) - 42*a(n-6)
for n>=6. For n<6, recurrence 1 can be used.

A360576 Number of 3-dimensional tilings of a 2 X 2 X n box using 1 X 1 X 1 cubes, 2 X 2 X 1 plates and trominos (L-shaped connection of 3 cubes).

Original entry on oeis.org

1, 6, 122, 1768, 28844, 457592, 7318760, 116806896, 1865305376, 29782666544, 475549098160, 7593154541264, 121241257906000, 1935879286697296, 30910512661708432, 493553365105565264, 7880649886335326608, 125831666350680625104
Offset: 0

Views

Author

Gerhard Kirchner, Feb 12 2023

Keywords

Comments

Recurrence 1 is derived in A359884, "3d-tilings of a 2 X 2 X n box" as a special case of a more general tiling problem: III, example 12.

Crossrefs

Formula

G.f.: (1-9*x+4*x^2-16*x^3) / (1-15*x-28*x^2+214*x^3-192*x^4-384*x^5+128*x^6).
Recurrence 1:
a(n) = 8*a(n-1) + 3*b(n-1) + 2*c(n-1) + d(n-1) + e(n-1) + 7*a(n-2)
b(n) = 12*a(n-1) + 5*b(n-1) + 2*c(n-1) + 2*d(n-1) + e(n-1)
c(n) = 16*a(n-1) + 4*b(n-1) + 2*c(n-1)
d(n) = 2*a(n-1) + b(n-1) + d(n-1)
e(n) = 12*a(n-1) + 3*b(n-1)
with a(n),b(n),c(n),d(n),e(n)= 0 for n<=0 except for a(0)=1.
Recurrence 2:
a(n)=15*a(n-1) + 28*a(n-2) - 214*a(n-3) + 192*a(n-4) + 384*a(n-5) - 128*a(n-6)
for n>=6. For n<6, recurrence 1 can be used.

A360577 Number of 3-dimensional tilings of a 2 X 2 X n box using 2 X 2 X 1 plates, 2 X 1 X 1 dominos and trominos (L-shaped connection of 3 cubes).

Original entry on oeis.org

1, 3, 60, 657, 8311, 101284, 1246049, 15292819, 187803572, 2305968393, 28315208039, 347681742812, 4269186204201, 52421329940803, 643681521419708, 7903765218510353, 97050331862075975, 1191681006432895780, 14632650860374551265, 179674317212728197891, 2206220907971874345652
Offset: 0

Views

Author

Gerhard Kirchner, Feb 12 2023

Keywords

Comments

Recurrence 1 is derived in A359884, "3d-tilings of a 2 X 2 X n box" as a special case of a more general tiling problem: III, example 13.

Crossrefs

Formula

G.f.: (1-5*x-15*x^2-3*x^3+10*x^4) / (1-8*x-51*x^2-27*x^3+96*x^4+43*x^5-66*x^6).
Recurrence 1:
a(n) = 3*a(n-1) + b(n-1) + c(n-1) + 19*a(n-2) + 4*b(n-2) + c(n-2) + 2*d(n-2)
b(n) = 12*a(n-1) + 2*b(n-1) + 2*c(n-1) + e(n-1)
c(n) = 20*a(n-1) + 6*b(n-1) + 2*c(n-1) + 2*e(n-1)
d(n) = 4*a(n-1) + 2*b(n-1) + d(n-1)
e(n) = 24*a(n-1) + 7*b(n-1) + 2*c(n-1) + 2*d(n-1)
with a(n),b(n),c(n),d(n),e(n)= 0 for n<=0 except for a(0)=1.
Recurrence 2:
a(n)=8*a(n-1) + 51*a(n-2) + 27*a(n-3) - 96*a(n-4) - 43*a(n-5) + 66*a(n-6)
for n>=6. For n<6, recurrence 1 can be used.

A360645 Number of 4-dimensional tilings of a 2 X 2 X 2 X n box with 2 X 2 X 1 X 1 plates.

Original entry on oeis.org

1, 3, 30, 177, 1281, 8520, 58629, 397887, 2715510, 18490533, 126023349, 858595560, 5850498441, 39863005323, 271617783150, 1850725023657, 12610357769721, 85923544106760, 585460036653789, 3989166905015367, 27181111280961990, 185204779320272253
Offset: 0

Views

Author

Gerhard Kirchner, Feb 15 2023

Keywords

Comments

The figure shows three 2 X 2 X 2 cubes as intersections of three successive hyperplanes (distance 1) with the box. The 3-d cross-section of a 2 X 2 X 1 X 1 plate is a 2 X 2 X 1 plate (p4) as part of one cube or a 2 X 1 X 1 domino if the plate (p2) connects two cubes. p4 or p2 indicates the number of unit cubes on the current level (hyperplane). PQRS and P'Q'R'S' (not visible: P') is one of three ways to select a pair of p4-plates. Q'Q"R"S' represents a p2-plate.
Suppose the box is completely tiled up to a certain level. Then the next (current) level may be empty (profile A0) or not (profile B0). The index 0 is used for the current level and continued with 1,2... Transitions:
a) A0->3*A1 (3 ways of selecting a pair of p4-plates, also A001045(2)=3).
b) A0->9*A2 (9 ways of tiling a 2 X 2 X 2 cube with 3d-dominos, also A006253(2)=9).
c) A0->12*B1. One p4-plate and two p2-plates can be selected in 12 ways: 6 faces of the 2 X 2 X 2 cube and two ways of selecting a pair of dominos on each face. They tile the next level with corresponding dominos. A further nonempty profile does not occur. Also, A359884(2)-A006253(2)-A001045(2)=24-9-3=12.
d) B0->1*A1 (one accomplishing p4-plate is placed on B0).
e) B0->*2B1 (2 ways of selecting a pair of dominos on B0).
Let a(n) and b(n) be the number of tilings of the 2 X 2 X 2 X n box ending with an A- or a B-profile respectively. With the transitions above, one obtains recurrence 1.
/\ /\ /\
/ \ / \ / \
/ \ S' /\ / \ /\ / \ /\
/ \ / \ / \ / \ / \ / \
|\ / \ /||\ / \ /||\ / \ /|
| \ / \ / || \ / \ / || \ / \ / |
| S |\ /| R'|| |\ /| R"|| |\ /| |---> 4th dimension
|\ | \ / | /||\ | \ / | /||\ | \ / | /|
| \| R | |/ || \| | |/ || \| | |/ |
| P |\ | /| Q'|| |\ | /| Q"|| |\ | /| |
\ | \|/ | / \ | \|/ | / \ | \|/ | /
\| Q | |/ \| | |/ \| | |/
\ | / \ | / \ | /
\|/ \|/ \|/

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{5, 15, -18}, {1, 3, 30}, 25] (* Paolo Xausa, May 28 2024 *)

Formula

Recurrence 1: a(n) = 3*a(n-1) + b(n-1) + 9*a(n-2), b(n) = 12*a(n-1) + 2*b(n-1), with a(0) = 1 and a(-1) = b(0) = 0.
Recurrence 2: a(n) = 5*a(n-1) + 15*a(n-2) - 18*a(n-3).
G.f.: (1-2*x) / (1-5*x-15*x^2+18*x^3).

A360644 Number of 3-dimensional tilings of a 2 X 2 X n box using 1 X 1 X 1 cubes, 2 X 1 X 1 dominos, 2 X 2 X 1 plates and trominos (L-shaped connection of 3 cubes).

Original entry on oeis.org

1, 12, 513, 16194, 547543, 18234354, 609298887, 20344385080, 679408772089, 22688284005780, 757662377924917, 25301659203704234, 844933359518672599, 28216027727373068302, 942256839186226313727, 31466085716246304261600, 1050790517091131646143477
Offset: 0

Views

Author

Gerhard Kirchner, Feb 15 2023

Keywords

Comments

Recurrence 1 is derived in A359884, "3d-tilings of a 2 X 2 X n box" as a special case of a more general tiling problem: III, example 14.

Crossrefs

Formula

G.f.: (1-16*x-18*x^2-13*x^3+10*x^4) / (1-28*x-195*x^2+497*x^3-30*x^4+79*x^5-66*x^6)
Recurrence 1:
a(n) = 12*a(n-1) + 4*b(n-1) + 2*c(n-1) + d(n-1) + e(n-1) + 43*a(n-2) + 8*b(n-2) + c(n-2) + 2*d(n-2)
b(n) = 32*a(n-1) + 9*b(n-1) + 4*c(n-1) + 2*d(n-1) + e(n-1)
c(n) = 60*a(n-1) + 16*b(n-1) + 6*c(n-1) + 4*d(n-1) + 2*e(n-1)
d(n) = 14*a(n-1) + 3*b(n-1) + d(n-1)
e(n) = 64*a(n-1) + 13*b(n-1) + 2*c(n-1) + 2*d(n-1)
with a(n),b(n),c(n),d(n),e(n)= 0 for n<=0 except for a(0)=1.
Recurrence 2:
a(n)=28*a(n-1) + 195*a(n-2) - 497*a(n-3) + 30*a(n-4) - 79*a(n-5) + 66*a(n-6)
for n>=6. For n<6, recurrence 1 can be used.
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