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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A250126 Coordination sequence of point of type 3.3.4.12 in 4-uniform tiling {3.3.4.3.4; 3.3.4.12; 3.3.12.4; 3.4.3.12}.

Original entry on oeis.org

1, 4, 9, 9, 12, 19, 21, 28, 27, 31, 38, 40, 48, 44, 49, 56, 57, 67, 63, 69, 73, 75, 85, 80, 88, 92, 95, 102, 98, 106, 109, 114, 121, 118, 123, 127, 132, 138, 137, 142, 147, 149, 156, 155, 159, 166, 168, 176, 172, 177, 184, 185, 195, 191, 197, 201, 203, 213, 208
Offset: 0

Views

Author

N. J. A. Sloane, Nov 29 2014

Keywords

Comments

This tiling appears as an example in Connelly et al. (2014), Fig. 6 (the heavy black lines in the figures here are an artifact from that figure).
For the definition of k-uniform tiling see Section 2.2 of Chapter 2 of Grünbaum and Shephard (1987).

References

  • Branko Grünbaum and G. C. Shephard, Tilings and Patterns. W. H. Freeman, New York, 1987.

Crossrefs

List of coordination sequences for uniform planar nets: A008458 (the planar net 3.3.3.3.3.3), A008486 (6^3), A008574 (4.4.4.4 and 3.4.6.4), A008576 (4.8.8), A008579 (3.6.3.6), A008706(3.3.3.4.4), A072154 (4.6.12), A219529 (3.3.4.3.4), A250120 (3.3.3.3.6), A250122 (3.12.12).

Formula

Empirical g.f.: -(2*x^16 +x^14 -2*x^12 -7*x^11 -10*x^10 -10*x^9 -14*x^8 -18*x^7 -17*x^6 -18*x^5 -12*x^4 -9*x^3 -9*x^2 -4*x -1) / ((x -1)^2*(x^4 +x^3 +x^2 +x +1)*(x^6 +x^5 +x^4 +x^3 +x^2 +x +1)). - Colin Barker, Dec 02 2014

Extensions

Galebach link from Joseph Myers, Nov 30 2014
Extended by Joseph Myers, Dec 02 2014

A299910 Coordination sequence of point of type 3.3.4.3.4 in 3-uniform tiling #3.54 in the Galebach listing.

Original entry on oeis.org

1, 5, 10, 17, 23, 28, 33, 40, 45, 48, 55, 63, 68, 71, 78, 85, 88, 93, 101, 108, 111, 116, 123, 128, 133, 139, 146, 151, 156, 161, 166, 173, 179, 184, 189, 196, 201, 204, 211, 219, 224, 227, 234, 241, 244, 249, 257, 264, 267, 272, 279, 284, 289, 295, 302, 307
Offset: 0

Views

Author

N. J. A. Sloane, Mar 07 2018

Keywords

Crossrefs

See A299909, A299911 for the other two kinds of points.

Programs

  • PARI
    \\ See Links section.

Formula

Conjectures from Chai Wah Wu, Jul 10 2025: (Start)
a(n) = a(n-1) - a(n-2) + a(n-3) + a(n-7) - a(n-8) + a(n-9) - a(n-10) for n > 10.
G.f.: (x^10 + 4*x^9 + 6*x^8 + 11*x^7 + 11*x^6 + 12*x^5 + 11*x^4 + 11*x^3 + 6*x^2 + 4*x + 1)/(x^10 - x^9 + x^8 - x^7 - x^3 + x^2 - x + 1). (End)

Extensions

More terms from Rémy Sigrist, May 10 2021

A299911 Coordination sequence of point of type 3.3.3.4.4 in 3-uniform tiling #3.54 in the Galebach listing.

Original entry on oeis.org

1, 5, 11, 16, 22, 29, 35, 38, 43, 51, 56, 60, 67, 75, 78, 81, 89, 96, 100, 105, 113, 118, 121, 127, 134, 140, 145, 151, 156, 161, 167, 172, 178, 185, 191, 194, 199, 207, 212, 216, 223, 231, 234, 237, 245, 252, 256, 261, 269, 274, 277, 283, 290, 296, 301, 307
Offset: 0

Views

Author

N. J. A. Sloane, Mar 07 2018

Keywords

Crossrefs

See A299909, A299910 for the other two kinds of points.

Programs

  • PARI
    \\ See Links section.

Formula

Conjectures from Chai Wah Wu, Jul 10 2025: (Start)
a(n) = a(n-1) - a(n-2) + a(n-3) + a(n-7) - a(n-8) + a(n-9) - a(n-10) for n > 10.
G.f.: (x^2 + x + 1)*(x^8 + 3*x^7 + 3*x^6 + 3*x^5 + 6*x^4 + 3*x^3 + 3*x^2 + 3*x + 1)/(x^10 - x^9 + x^8 - x^7 - x^3 + x^2 - x + 1). (End)

Extensions

More terms from Rémy Sigrist, May 10 2021

A316316 Coordination sequence for tetravalent node in chamfered version of square grid.

Original entry on oeis.org

1, 4, 8, 8, 12, 20, 20, 20, 28, 32, 32, 36, 40, 44, 48, 48, 52, 60, 60, 60, 68, 72, 72, 76, 80, 84, 88, 88, 92, 100, 100, 100, 108, 112, 112, 116, 120, 124, 128, 128, 132, 140, 140, 140, 148, 152, 152, 156, 160, 164, 168, 168, 172, 180, 180, 180, 188, 192, 192
Offset: 0

Views

Author

N. J. A. Sloane, Jun 29 2018

Keywords

Crossrefs

See A316317 for trivalent node.
See A250120 for links to thousands of other coordination sequences.
Cf. A316357 (partial sums).

Programs

  • Mathematica
    Join[{1}, LinearRecurrence[{1, -1, 2, -1, 1, -1}, {4, 8, 8, 12, 20, 20}, 100]] (* Jean-François Alcover, Dec 13 2018 *)
  • PARI
    See Links section.

Formula

Apparently, a(n + 12) = a(n) + 40 for any n > 0. - Rémy Sigrist, Jun 30 2018
From N. J. A. Sloane, Jun 30 2018: This conjecture is true.
Theorem: a(n + 12) = a(n) + 40 for any n > 0.
The proof uses the Coloring Book Method described in the Goodman-Strauss - Sloane article. For details see the two links.
From Colin Barker, Dec 13 2018: (Start)
G.f.: (1 + 3*x + 5*x^2 + 2*x^3 + 5*x^4 + 3*x^5 + x^6) / ((1 - x)^2*(1 + x^2)*(1 + x + x^2)).
a(n) = a(n-1) - a(n-2) + 2*a(n-3) - a(n-4) + a(n-5) - a(n-6) for n>6.
(End)
a(n) = (2/9)*(15*n + 9*A056594(n-1) - 6*A102283(n)) for n > 0. - Stefano Spezia, Jun 12 2021

Extensions

More terms from Rémy Sigrist, Jun 30 2018

A316317 Coordination sequence for trivalent node in chamfered version of square grid.

Original entry on oeis.org

1, 3, 6, 11, 14, 15, 20, 25, 26, 29, 34, 37, 40, 43, 46, 51, 54, 55, 60, 65, 66, 69, 74, 77, 80, 83, 86, 91, 94, 95, 100, 105, 106, 109, 114, 117, 120, 123, 126, 131, 134, 135, 140, 145, 146, 149, 154, 157, 160, 163, 166, 171, 174, 175, 180, 185, 186, 189, 194
Offset: 0

Views

Author

N. J. A. Sloane, Jun 29 2018

Keywords

Crossrefs

See A316316 for tetravalent node.
See A250120 for links to thousands of other coordination sequences.
Cf. A316358 (partial sums).

Programs

  • PARI
    See Links section.

Formula

Apparently, a(n + 12) = a(n) + 40 for any n > 0. - Rémy Sigrist, Jun 30 2018
This can surely be proved by the Coloring Book Method, although I have not worked out the details. See A316316 for the corresponding proof for a tetravalent node. - N. J. A. Sloane, Jun 30 2018
G.f. (assuming above conjecture): (1+x)^2*(1+3*x^2+x^4)/((1-x)^2*(1+x+x^2)*(1+x^2)). - Robert Israel, Jul 01 2018
a(n) = (30*n - 9*A056594(n-1) + 6*A102283(n))/9 for n > 0. - Conjectured by Stefano Spezia, Jun 12 2021

Extensions

More terms from Rémy Sigrist, Jun 30 2018

A299909 Coordination sequence of node of type 3^6 in 3-uniform tiling #3.54 in the Galebach listing.

Original entry on oeis.org

1, 6, 12, 18, 24, 24, 30, 42, 48, 48, 54, 66, 66, 66, 78, 90, 90, 90, 102, 108, 108, 114, 126, 132, 132, 138, 144, 150, 156, 162, 168, 174, 180, 180, 186, 198, 204, 204, 210, 222, 222, 222, 234, 246, 246, 246, 258, 264, 264, 270, 282, 288, 288, 294, 300, 306
Offset: 0

Views

Author

N. J. A. Sloane, Mar 07 2018

Keywords

Comments

This tiling has three kinds of nodes. So far the other two types (A299910, A299911) have nor been analyzed.

Crossrefs

See A299910, A299911 for the other two kinds of nodes.

Programs

  • Mathematica
    Join[{1}, LinearRecurrence[{1, -1, 1, 0, 0, 0, 1, -1, 1, -1}, {6, 12, 18, 24, 24, 30, 42, 48, 48, 54}, 60]] (* Jean-François Alcover, Jan 09 2019 *)
  • PARI
    Vec((x^10+5*x^9+7*x^8+11*x^7+12*x^6+6*x^5+12*x^4+11*x^3+7*x^2+5*x+1) / ((1-x)^2*(1+x^2)*(x^6+x^5+x^4+x^3+x^2+x+1)) + O(x^60)) \\ Colin Barker, Mar 11 2018

Formula

G.f.: (x^10+5*x^9+7*x^8+11*x^7+12*x^6+6*x^5+12*x^4+11*x^3+7*x^2+5*x+1) / ((1-x)^2*(1+x^2)*(x^6+x^5+x^4+x^3+x^2+x+1)).
The denominator can also be written as (1-x)*(1+x^2)*(1-x^7).
Recurrence: (-n^2-5*n)*a(n)-n*a(n+1)+
(-n^2-6*n)*a(n+2)-2*n*a(n+3)-2*n*a(n+4)-2*n*a(n+5)-
2*n*a(n+6)+(n^2+3*n)*a(n+7)-n*a(n+8)+(n^2+4*n)*a(n+9) = 0,
with a(0) = 1, a(1) = 6, a(2) = 12, a(3) = 18, a(4) = 24, a(5) = 24, a(6) = 30, a(7) = 42, a(8) = 48, a(9) = 48.
a(n) = a(n-1) - a(n-2) + a(n-3) + a(n-7) - a(n-8) + a(n-9) - a(n-10) for n>10. - Colin Barker, Mar 11 2018
Details of the calculation of the generations function. (Start)
The following lines are written in Maple notation, but should be intelligible as plain text. The colors refer to the labeling of one sector shown in the link.
This analysis did not directly use the "trunks and branches" method described in the Goodman-Strauss & Sloane paper, but was influenced by it.
# The generating function for one of the six sectors:
G:=1+2*x+2*x^2+2*x^3; # green sausages
QG:=G/((1-x^4)*(1-x^7)); # the lattice of green sausages
R:=2+2*x+2*x^2+x^3; # red sausages
QR:=R*(1/(1-x^3))*(x^4/(1-x^4)-x^7/(1-x^7)); # lattice of red sausages
XA:=-x^2/(1-x); # correction for "X-axis"
# red vertical lines of type a
RVLa := x^2/((1-x)*(1-x^4))+x^5*(1/(1-x^3))*(1/(1-x^4)-1/(1-x^7));
# red vertical lines of type b
RVLb:= x^3/((1-x^4)*(1-x^7)) + x^7/((1-x^3)*(1-x^4)) - x^10/((1-x^3)*(1-x^7));
# red vertical lines of type c (twigs to right of vertical sausages)
RVLc:= x^4/((1-x^4)*(1-x^7)) + x^8/((1-x^3)*(1-x^4)) - x^11/((1-x^3)*(1-x^7));
# Total for one sector
T:=QG+QR+XA+RVLa+RVLb+RVLc;
# Grand total, after correcting for overcounting where sectors meet:
U:=6*T-5-6*x;
series(U,x,30);
# After simplification, grand total is:
(x^10+5*x^9+7*x^8+11*x^7+12*x^6+6*x^5+12*x^4+11*x^3+7*x^2+5*x+1) / ((1-x)^2*(1+x^2)*(x^6+x^5+x^4+x^3+x^2+x+1));
(End) (These details added by N. J. A. Sloane, Apr 10 2018)

A350963 Coordination sequence for the XXOXX tiling with respect to a tile of type R.

Original entry on oeis.org

1, 9, 29, 42, 63, 75, 97, 106, 131, 139, 165, 170, 199, 203, 233, 234, 267, 267, 301, 298, 335, 331, 369, 362, 403, 395, 437, 426, 471, 459, 505, 490, 539, 523, 573, 554, 607, 587, 641, 618, 675, 651, 709, 682, 743, 715, 777, 746, 811, 779, 845, 810, 879, 843
Offset: 0

Views

Author

N. J. A. Sloane, Feb 25 2022

Keywords

Comments

The tile consists of five squares in a row with the center square missing. The tiling of the plane studied here is that shown in Fig. 2 of Gruslys et al., and in the other illustrations below. (An email from Neil Bickford suggests that this may be the unique tiling of the plane using this tile.)
There are three orbits on tiles, which we denote by R, G, and B, corresponding to the colors in the illustrations. The tiles are drawn as two dominoes linked by a thin bridge. The symmetry group appears to be p2.
For the coordination sequence we regard two tiles as adjacent if they share a (long or short) edge. The two halves of a tile are marked with its generation number. The base (R) tile is marked with two 0's and is enclosed in a black border. The 9 generation 1 tiles are marked with two 1's and two black stars.
Each R tile touches 4 R's, 4 G's, and 1 B; each G tile touches 4 R's, 1 G, and 3 B's; each B tile touches 1 R, 3 G's, and 4 B's.

Crossrefs

Cf. A351966 (type G), A351967 (type B).
See A250120 for other examples of coordination sequences.

Programs

  • PARI
    See Links section.

Formula

Conjectured g.f.: -(2*t^7-6*t^6-24*t^5-33*t^4-33*t^3-28*t^2-9*t-1)/((1-t^2)*(1-t^4)). Given the decomposition of this structure into eight sectors (see Sigrist's illustration of the first 100 generations), it should be possible to establish this g.f. and those of the other two coordination sequences by using the coloring book method. - N. J. A. Sloane, Feb 26 2022

Extensions

More terms from Rémy Sigrist, Feb 26 2022

A315431 Coordination sequence Gal.6.669.6 where Gal.u.t.v denotes the coordination sequence for a vertex of type v in tiling number t in the Galebach list of u-uniform tilings.

Original entry on oeis.org

1, 6, 11, 15, 22, 28, 33, 39, 44, 52, 56, 61, 64, 74, 78, 83, 88, 98, 100, 105, 110, 120, 120, 129, 132, 142, 142, 153, 154, 164, 166, 175, 174, 186, 188, 197, 196, 212, 210, 219, 218, 234, 230, 241, 242, 256, 252, 265, 264, 278
Offset: 0

Views

Author

Brian Galebach and N. J. A. Sloane, Jun 18 2018

Keywords

Comments

Note that there may be other vertices in the Galebach list of u-uniform tilings with u <= 6 that have this same coordination sequence. See the Galebach link for the complete list of A-numbers for all these tilings.

Formula

From Chai Wah Wu, Dec 20 2019: (Start)
a(n) = a(n-4) - a(n-5) + a(n-7) + a(n-9) - a(n-11) + a(n-12) - a(n-16) for n > 22 (conjectured).
G.f.: (-x^22 - x^17 + x^16 + 8*x^15 + 11*x^14 + 16*x^13 + 21*x^12 + 23*x^11 + 30*x^10 + 34*x^9 + 31*x^8 + 34*x^7 + 28*x^6 + 23*x^5 + 21*x^4 + 15*x^3 + 11*x^2 + 6*x + 1)/(x^16 - x^12 + x^11 - x^9 - x^7 + x^5 - x^4 + 1) (conjectured). (End)

A315440 Coordination sequence Gal.6.491.5 where Gal.u.t.v denotes the coordination sequence for a vertex of type v in tiling number t in the Galebach list of u-uniform tilings.

Original entry on oeis.org

1, 6, 11, 16, 19, 26, 32, 36, 41, 46, 47, 56, 64, 68, 75, 76, 79, 86, 92, 98, 107, 106, 109, 118, 122, 130, 137, 140, 141, 146, 152, 160, 165, 170, 175, 178, 184, 190, 197, 200, 203, 210, 216, 218, 227, 232, 233, 242, 248, 252
Offset: 0

Views

Author

Brian Galebach and N. J. A. Sloane, Jun 18 2018

Keywords

Comments

Note that there may be other vertices in the Galebach list of u-uniform tilings with u <= 6 that have this same coordination sequence. See the Galebach link for the complete list of A-numbers for all these tilings.

A315442 Coordination sequence Gal.6.428.5 where Gal.u.t.v denotes the coordination sequence for a vertex of type v in tiling number t in the Galebach list of u-uniform tilings.

Original entry on oeis.org

1, 6, 11, 16, 20, 22, 30, 33, 40, 46, 54, 55, 62, 64, 66, 74, 75, 86, 92, 100, 99, 110, 108, 110, 120, 119, 130, 136, 146, 143, 156, 152, 156, 166, 163, 176, 182, 190, 185, 202, 196, 200, 212, 209, 222, 228, 236, 229, 246, 238
Offset: 0

Views

Author

Brian Galebach and N. J. A. Sloane, Jun 18 2018

Keywords

Comments

Note that there may be other vertices in the Galebach list of u-uniform tilings with u <= 6 that have this same coordination sequence. See the Galebach link for the complete list of A-numbers for all these tilings.
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