A072154 -id:A072154 - cp's OEIS frontend

A008579 Coordination sequence for planar net 3.6.3.6. Spherical growth function for a certain reflection group in plane.

1, 4, 8, 14, 18, 22, 28, 30, 38, 38, 48, 46, 58, 54, 68, 62, 78, 70, 88, 78, 98, 86, 108, 94, 118, 102, 128, 110, 138, 118, 148, 126, 158, 134, 168, 142, 178, 150, 188, 158, 198, 166, 208, 174, 218, 182, 228, 190, 238, 198, 248, 206, 258, 214, 268, 222, 278

Offset: 0

N. J. A. Sloane

Interesting because coefficients never become monotonic.
Also the coordination sequence for a planar net made of densely packed circles. - Yuriy Sibirmovsky, Sep 11 2016
Described by J.-G. Eon (2014) as the coordination sequence of the Kagome net. - N. J. A. Sloane, Jan 03 2018

P. de la Harpe, Topics in Geometric Group Theory, Univ. Chicago Press, 2000, p. 161 (but beware errors).

T. D. Noe, Table of n, a(n) for n = 0..1000
Pierre de La Harpe, and P. I. Grigorchuk, Local convexity of the growth function of finitely generated groups and question 5.2 in the Kourovka Notebook, Algebra and Logic 37.6 (1998): 353-356.
Jean-Guillaume Eon, Algebraic determination of generating functions for coordination sequences in crystal structures, Acta Cryst. A58 (2002), 47-53. See p. 51.
Jean-Guillaume Eon, Topological density of nets: a direct calculation, Acta Crystallographica Section A (Foundations of Crystallography), A60 (2014), 7-18; DOI: 10.1107/S0108767303022037. See Section 5.
Jean-Guillaume Eon, Symmetry and Topology: The 11 Uninodal Planar Nets Revisited, Symmetry, 10 (2018), 13 pages, doi:10.3390/sym10020035. See Section 4.
Brian Galebach, k-uniform tilings (k <= 6) and their A-numbers
Chaim Goodman-Strauss and N. J. A. Sloane, A Coloring Book Approach to Finding Coordination Sequences, Acta Cryst. A75 (2019), 121-134, also on NJAS's home page. Also arXiv:1803.08530.
Branko Grünbaum and Geoffrey C. Shephard, Tilings by regular polygons, Mathematics Magazine, 50 (1977), 227-247.
Tom Karzes, Tiling Coordination Sequences
Reticular Chemistry Structure Resource, kgm
Yuriy Sibirmovsky, Illustration of initial terms with densely packed circles.
N. J. A. Sloane, Illustration of initial terms
N. J. A. Sloane, The uniform planar nets and their A-numbers [Annotated scanned figure from Gruenbaum and Shephard (1977)]
Index entries for linear recurrences with constant coefficients, signature (0,2,0,-1).

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).

Cf. A017137, A017365.

a008579 0 = 1
a008579 1 = 4
a008579 n = (10 - 2*m) * n' + 8*m - 2 where (n',m) = divMod n 2
a008579_list = 1 : 4 : concatMap (\x -> map (* 2) [5*x-1,4*x+3]) [1..]
-- Reinhard Zumkeller, Nov 12 2012

f := n->if n mod 2 = 0 then 10*(n/2)-2 else 8*(n-1)/2+6 fi;

a[n_?EvenQ] := 10*n/2-2; a[n_?OddQ] := 8*(n-1)/2+6; a[0] = 1; a[1] = 4; Table[a[n], {n, 0, 45}] (* Jean-François Alcover, Nov 18 2011, after Maple *)
CoefficientList[Series[(1+2x)(1+2x+2x^2+2x^3-x^4)/(1-x^2)^2,{x,0,50}],x] (* or *) LinearRecurrence[{0,2,0,-1},{1,4,8,14,18,22},50] (* Harvey P. Dale, Sep 05 2018 *)

G.f.: (1 + 2*x)*(1 + 2*x + 2*x^2 + 2*x^3 - x^4)/(1 - x^2)^2.
From R. J. Mathar, Nov 26 2014: (Start)
a(2n) = A017365(n), n > 0.
a(2n+1) = A017137(n), n > 0. (End)
From Stefano Spezia, Aug 07 2022: (Start)
a(n) = (9 + (-1)^n)*n/2 - 2*(-1)^n for n > 1.
E.g.f.: 3 - 2*x + (4*x - 2)*cosh(x) + (5*x + 2)*sinh(x). (End)

A250122 Coordination sequence for planar net 3.12.12.

Original entry on oeis.org

1, 3, 4, 6, 8, 12, 14, 15, 18, 21, 22, 24, 28, 30, 30, 33, 38, 39, 38, 42, 48, 48, 46, 51, 58, 57, 54, 60, 68, 66, 62, 69, 78, 75, 70, 78, 88, 84, 78, 87, 98, 93, 86, 96, 108, 102, 94, 105, 118, 111, 102, 114, 128, 120, 110, 123, 138, 129

Offset: 0

Darrah Chavey, Nov 23 2014

Also, growth series for group with presentation < S, T : S^2 = T^3 = (S*T)^6 = 1 >. See Magma program in A298805. - N. J. A. Sloane, Feb 06 2018

Maurizio Paolini, Table of n, a(n) for n = 0..1021
Agnes Azzolino, Regular and Semi-Regular Tessellation Paper, 2011.
Agnes Azzolino, Illustration of 3.12.12 tiling [From previous link]
Brian Galebach, k-uniform tilings (k <= 6) and their A-numbers
Chaim Goodman-Strauss and N. J. A. Sloane, A Coloring Book Approach to Finding Coordination Sequences, Acta Cryst. A75 (2019), 121-134, also on NJAS's home page. Also on arXiv, arXiv:1803.08530 [math.CO], 2018-2019. See section 10 The 3.12^2 tiling.
Rostislav Grigorchuk and Cosmas Kravaris, On the growth of the wallpaper groups, arXiv:2012.13661 [math.GR], 2020. See section 4.6 p. 23.
Branko Grünbaum and Geoffrey C. Shephard, Tilings by regular polygons, Mathematics Magazine, 50 (1977), 227-247.
Tom Karzes, Tiling Coordination Sequences
Maurizio Paolini, C program for A250122
Reticular Chemistry Structure Resource, hca
N. J. A. Sloane, The uniform planar nets and their A-numbers [Annotated scanned figure from Gruenbaum and Shephard (1977)]
Index entries for linear recurrences with constant coefficients, signature (2,-3,4,-3,2,-1).

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).

Cf. A298805.

Join[{1, 3, 4}, LinearRecurrence[{2, -3, 4, -3, 2, -1}, {6, 8, 12, 14, 15, 18}, 100]] (* Jean-François Alcover, Aug 05 2018 *)

From Joseph Myers, Nov 28 2014: (Start)
Empirically,
a(4n) = 10n - 2 except for a(0) = 1
a(4n+1) = 9n + 3
a(4n+2) = 8n + 6 except for a(2) = 4
a(4n+3) = 9n + 6. (End)
If these are correct, the sequence has g.f.
-(-1 - x - x^2 - 3*x^3 + x^4 - 5*x^5 + 3*x^6 - 4*x^7 + 2*x^8)/((x - 1)^2*(x^2 + 1)^2). - N. J. A. Sloane, Nov 28 2014
All the above conjectures are true. - N. J. A. Sloane, Dec 31 2015
E.g.f.: (9*x*cosh(x) - 4*(2*cos(x) + x^2 - 3) + 9*x*sinh(x) - (x - 3)*sin(x))/4. - Stefano Spezia, Jan 05 2023

a(8) onwards from Maurizio Paolini and Joseph Myers (independently), Nov 28 2014

A008706 Coordination sequence for 3.3.3.4.4 planar net.

Original entry on oeis.org

1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275

Offset: 0

N. J. A. Sloane

Also the Engel expansion of exp^(1/5); cf. A006784 for the Engel expansion definition. - Benoit Cloitre, Mar 03 2002

			G.f. = 1 + 5*x + 10*x^2 + 15*x^3 + 20*x^4 + 25*x^5 + 30*x^6 + 35*x^7 + ...

Vincenzo Librandi, Table of n, a(n) for n = 0..10000
Brian Galebach, k-uniform tilings (k <= 6) and their A-numbers
Chaim Goodman-Strauss and N. J. A. Sloane, A Coloring Book Approach to Finding Coordination Sequences, Acta Cryst. A75 (2019), 121-134, also on NJAS's home page. Also arXiv:1803.08530.
Branko Grünbaum and Geoffrey C. Shephard, Tilings by regular polygons, Mathematics Magazine, 50 (1977), 227-247.
Tom Karzes, Tiling Coordination Sequences
Reticular Chemistry Structure Resource, cem
N. J. A. Sloane, The uniform planar nets and their A-numbers [Annotated scanned figure from Gruenbaum and Shephard (1977)]
Index entries for linear recurrences with constant coefficients, signature (2,-1).

Cf. A006784, A048476 (binomial Transf.)
Essentially the same as A008587.
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).
First differences of A005891.

[0^n+5*n: n in [0..50] ]; // Vincenzo Librandi, Aug 21 2011

Join[{1}, LinearRecurrence[{2, -1}, {5, 10}, 100]] (* Jean-François Alcover, Dec 13 2018 *)

a(n)=0^n+5*n \\ Charles R Greathouse IV, Mar 19 2015

From Paul Barry, Jul 21 2003: (Start)
G.f.: (1 + 3*x + x^2)/(1 - x)^2.
a(n) = 0^n + 5n. (End)
G.f.: A(x) + 1, where A(x) is the g.f. of A008587. - Gennady Eremin, Feb 21 2021
E.g.f.: 1 + 5*x*exp(x). - Stefano Spezia, Jan 05 2023

A296368 Coordination sequence for the Cairo or dual-3.3.4.3.4 tiling with respect to a trivalent point.

Original entry on oeis.org

1, 3, 8, 12, 15, 20, 25, 28, 31, 36, 41, 44, 47, 52, 57, 60, 63, 68, 73, 76, 79, 84, 89, 92, 95, 100, 105, 108, 111, 116, 121, 124, 127, 132, 137, 140, 143, 148, 153, 156, 159, 164, 169, 172, 175, 180, 185, 188, 191, 196, 201, 204, 207, 212, 217, 220, 223, 228

Offset: 0

N. J. A. Sloane, Dec 21 2017

There are two types of point in this tiling. This is the coordination sequence with respect to a point of degree 3.

The coordination sequence with respect to a point of degree 4 (see second illustration) is simply 1, 4, 8, 12, 16, 20, ..., the same as the coordination sequence for the 4.4.4.4 square grid (A008574). See the CGS-NJAS link for the proof.

Branko Grünbaum and G. C. Shephard, Tilings and Patterns. W. H. Freeman, New York, 1987. See Fig. 9.1.3, drawing P_5-24, page 480.
Herbert C. Moore, U.S. Patents 928,320 and 928,321, Patented July 20 1909. [Shows Cairo tiling.]

Rémy Sigrist, Table of n, a(n) for n = 0..1000
Chaim Goodman-Strauss and N. J. A. Sloane, A portion of the Cairo tiling
Chaim Goodman-Strauss and N. J. A. Sloane, A Coloring Book Approach to Finding Coordination Sequences, Acta Cryst. A75 (2019), 121-134, also on NJAS's home page. Also arXiv:1803.08530.
Chung, Ping Ngai, Miguel A. Fernandez, Yifei Li, Michael Mara, Frank Morgan, Isamar Rosa Plata, Niralee Shah, Luis Sordo Vieira, and Elena Wikner. Isoperimetric Pentagonal Tilings, Notices of the AMS 59, no. 5 (2012), pp. 632-640. See Fig. 1 (left).
Tom Karzes, Tiling Coordination Sequences
Frank Morgan, Optimal Pentagonal Tilings, Video, May 2021 [Has much to say about the Cairo tiling]
Reticular Chemistry Structure Resource (RCSR), The mcm tiling (or net)
Rémy Sigrist, PARI program for A296368
N. J. A. Sloane, Illustration of initial terms (for a trivalent point)
N. J. A. Sloane, Illustration of initial terms of coordination sequence 1,4,8,12,... for a tetravalent point
N. J. A. Sloane, A tiling by rectangles which has the same graph and coordination sequences as the Cairo tiling (Seen on the streets of Piscataway, New Jersey, USA)
N. J. A. Sloane, Overview of coordination sequences of Laves tilings [Fig. 2.7.1 of Grünbaum-Shephard 1987 with A-numbers added and in some cases the name in the RCSR database]
N. J. A. Sloane, Coordination Sequences, Planing Numbers, and Other Recent Sequences (II), Experimental Mathematics Seminar, Rutgers University, Jan 31 2019, Part I, Part 2, Slides. (Mentions this sequence)
Index entries for linear recurrences with constant coefficients, signature (2, -2, 2, -1).

For partial sums see A296909.
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).
List of coordination sequences for Laves tilings (or duals of uniform planar nets): [3,3,3,3,3.3] = A008486; [3.3.3.3.6] = A298014, A298015, A298016; [3.3.3.4.4] = A298022, A298024; [3.3.4.3.4] = A008574, A296368; [3.6.3.6] = A298026, A298028; [3.4.6.4] = A298029, A298031, A298033; [3.12.12] = A019557, A298035; [4.4.4.4] = A008574; [4.6.12] = A298036, A298038, A298040; [4.8.8] = A022144, A234275; [6.6.6] = A008458.

Join[{1, 3, 8}, LinearRecurrence[{2, -2, 2, -1}, {12, 15, 20, 25}, 100]] (* Jean-François Alcover, Aug 05 2018 *)

PARI
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\\ See Links section.
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The simplest formula is: a(0)=1, a(1)=2, a(2)=8, and thereafter a(n) = 4n if n is odd, 4n - 1 if n == 0 (mod 4), and 4n+1 if n == 2 (mod 4). (See the CGS-NJAS link for proof. - N. J. A. Sloane, May 10 2018)
a(n + 4) = a(n) + 16 for any n >= 3. - Rémy Sigrist, Dec 23 2017 (See the CGS-NJAS link for a proof. - N. J. A. Sloane, Dec 30 2017)
G.f.: -(x^6-x^5-2*x^4-4*x^2-x-1)/((x^2+1)*(x-1)^2).
From Colin Barker, Dec 23 2017: (Start)
a(n) = (8*n - (-i)^n - i^n) / 2 for n>2, where i=sqrt(-1).
a(n) = 2*a(n-1) - 2*a(n-2) + 2*a(n-3) - a(n-4) for n>6.
(End)

Terms a(8)-a(20) and RCSR link from Davide M. Proserpio, Dec 22 2017

More terms from Rémy Sigrist, Dec 23 2017

A298036 Coordination sequence of Dual(4.6.12) tiling with respect to a 12-valent node.

Original entry on oeis.org

1, 12, 12, 36, 24, 60, 36, 84, 48, 108, 60, 132, 72, 156, 84, 180, 96, 204, 108, 228, 120, 252, 132, 276, 144, 300, 156, 324, 168, 348, 180, 372, 192, 396, 204, 420, 216, 444, 228, 468, 240, 492, 252, 516, 264, 540, 276, 564, 288, 588, 300

Offset: 0

N. J. A. Sloane, Jan 22 2018

Conjecture: For n>0, a(n)=6n if n even, otherwise 12n.

The conjecture can easily be shown to be true: The vertices at distance 2k consist of 3k 12-valent and 3k 4-alent vertices, and the vertices at distance 2k+1 consist of 6(k+1) 6-valent and 6(k+1) 4-valent vertices. - Charlie Neder, Apr 22 2019

Hakan Icoz, Table of n, a(n) for n = 0..20000
Tom Karzes, Tiling Coordination Sequences
N. J. A. Sloane, Illustration of initial terms (shows one 60-degree sector of tiling)
N. J. A. Sloane, Overview of coordination sequences of Laves tilings [Fig. 2.7.1 of Grünbaum-Shephard 1987 with A-numbers added and in some cases the name in the RCSR database]
Index entries for linear recurrences with constant coefficients, signature (0,2,0,-1).

Cf. A072154, A298037 (partial sums), A298038 (hexavalent node), A298040 (tetravalent node).
Cf. A109043 (a(n)/6), A026741 (a(n)/12).
List of coordination sequences for Laves tilings (or duals of uniform planar nets): [3,3,3,3,3.3] = A008486; [3.3.3.3.6] = A298014, A298015, A298016; [3.3.3.4.4] = A298022, A298024; [3.3.4.3.4] = A008574, A296368; [3.6.3.6] = A298026, A298028; [3.4.6.4] = A298029, A298031, A298033; [3.12.12] = A019557, A298035; [4.4.4.4] = A008574; [4.6.12] = A298036, A298038, A298040; [4.8.8] = A022144, A234275; [6.6.6] = A008458.

LinearRecurrence[{0, 2, 0, -1}, {1, 12, 12, 36, 24}, 100] (* Paolo Xausa, Jul 19 2024 *)

From Charlie Neder, Apr 22 2019: (Start)
a(n) = 6 * n * (1 + n mod 2), n > 0.
G.f.: (1 + 12*x + 10*x^2 + 12*x^3 + x^4)/(1 - x^2)^2. (End)

a(7)-a(50) from Charlie Neder, Apr 22 2019

A298038 Coordination sequence of Dual(4.6.12) tiling with respect to a hexavalent node.

Original entry on oeis.org

1, 6, 24, 18, 48, 30, 72, 42, 96, 54, 120, 66, 144, 78, 168, 90, 192, 102, 216, 114, 240, 126, 264, 138, 288, 150, 312, 162, 336, 174, 360, 186, 384, 198, 408, 210, 432, 222, 456, 234, 480, 246, 504, 258, 528, 270, 552, 282, 576, 294, 600, 306, 624, 318, 648

Offset: 0

N. J. A. Sloane, Jan 22 2018

nonn

Conjecture: For n > 0, a(n)=12n if n even, otherwise 6n.
From Keagan Boyce, May 18 2024: (Start)
It appears that
  a(n) = (3*n)*(3+(-1)^n) for n > 0,
which would imply that for all even n > 0,
  a(n) = (3*n)*(3+(1)) = (3*n)*(4) = 12*n,
and for all odd n > 0,
  a(n) = (3*n)*(3+(-1)) = (3*n)*(2) = 6*n. (End)

Tom Karzes, Tiling Coordination Sequences.
N. J. A. Sloane, Illustration of initial terms (shows one 60-degree sector of tiling).
N. J. A. Sloane, Overview of coordination sequences of Laves tilings [Fig. 2.7.1 of Grünbaum-Shephard 1987 with A-numbers added and in some cases the name in the RCSR database].

Cf. A072154, A298039 (partial sums), A298036 (12-valent node), A298040 (tetravalent node).

List of coordination sequences for Laves tilings (or duals of uniform planar nets): [3,3,3,3,3.3] = A008486; [3.3.3.3.6] = A298014, A298015, A298016; [3.3.3.4.4] = A298022, A298024; [3.3.4.3.4] = A008574, A296368; [3.6.3.6] = A298026, A298028; [3.4.6.4] = A298029, A298031, A298033; [3.12.12] = A019557, A298035; [4.4.4.4] = A008574; [4.6.12] = A298036, A298038, A298040; [4.8.8] = A022144, A234275; [6.6.6] = A008458.

Conjectures from Colin Barker, Apr 03 2020: (Start)
G.f.: (1 + 6*x + 22*x^2 + 6*x^3 + x^4) / ((1 - x)^2*(1 + x)^2).
a(n) = 2*a(n-2) - a(n-4) for n > 4. (End)

Terms a(8)-a(54) added by Tom Karzes, Apr 01 2020

A298040 Coordination sequence of Dual(4.6.12) tiling with respect to a tetravalent node.

Original entry on oeis.org

1, 4, 20, 24, 40, 40, 60, 56, 80, 72, 100, 88, 120, 104, 140, 120, 160, 136, 180, 152, 200, 168, 220, 184, 240, 200, 260, 216, 280, 232, 300, 248, 320, 264, 340, 280, 360, 296, 380, 312, 400, 328, 420, 344, 440, 360, 460, 376, 480, 392, 500, 408, 520, 424, 540

Offset: 0

N. J. A. Sloane, Jan 22 2018

Harvey P. Dale, Table of n, a(n) for n = 0..1000
Tom Karzes, Tiling Coordination Sequences
N. J. A. Sloane, Illustration of initial terms (shows one 90-degree quadrant of tiling)
N. J. A. Sloane, Overview of coordination sequences of Laves tilings [Fig. 2.7.1 of Grünbaum-Shephard 1987 with A-numbers added and in some cases the name in the RCSR database]
Index entries for linear recurrences with constant coefficients, signature (0,2,0,-1).

Cf. A072154, A298041 (partial sums), A298036 (12-valent node), A298038 (hexavalent node).

List of coordination sequences for Laves tilings (or duals of uniform planar nets): [3,3,3,3,3.3] = A008486; [3.3.3.3.6] = A298014, A298015, A298016; [3.3.3.4.4] = A298022, A298024; [3.3.4.3.4] = A008574, A296368; [3.6.3.6] = A298026, A298028; [3.4.6.4] = A298029, A298031, A298033; [3.12.12] = A019557, A298035; [4.4.4.4] = A008574; [4.6.12] = A298036, A298038, A298040; [4.8.8] = A022144, A234275; [6.6.6] = A008458.

LinearRecurrence[{0,2,0,-1},{1,4,20,24,40,40},60] (* Harvey P. Dale, Apr 06 2022 *)

Conjecture: For n>0, a(n)=10n if n even, otherwise 8n.
Conjectures from Colin Barker, Apr 01 2020: (Start)
G.f.: (1 + 4*x + 18*x^2 + 16*x^3 + x^4 - 4*x^5) / ((1 - x)^2*(1 + x)^2).
a(n) = (9 + (-1)^n)*n for n>1.
a(n) = 2*a(n-2) - a(n-4) for n>5.
(End)

Terms a(8)-a(54) added by Tom Karzes, Apr 01 2020

A072149 Coordination sequence for AlPO_4-11 structure with respect to node (X) where decagon and two hexagons meet.

Original entry on oeis.org

1, 3, 6, 8, 10, 13, 16, 19, 20, 22, 28, 31, 30, 33, 38, 40, 42, 43, 46, 53, 54, 52, 58, 63, 62, 65, 68, 70, 76, 77, 76, 83, 86, 84, 90, 93, 92, 99, 102, 100, 106, 109, 108, 115, 116, 114, 124, 127, 122, 129, 134, 132, 138, 139, 138, 149, 150, 144, 154, 159

Offset: 0

N. J. A. Sloane, Jun 28 2002

There are three types of nodes in this structure.

The coordination sequence with respect to a particular node gives the number of nodes that can be reached from that node in n steps along edges.

Joseph Myers, Table of n, a(n) for n = 0..1000
M. E. Davis, Ordered porous materials for emerging applications, Nature, 417 (Jun 20 2002), 813-821 (gives structure).
N. J. A. Sloane, AlPO_4-11 structure, after Davis
R. J. Mathar, Illustration of counts and adjacencies (PostScript)

Cf. A072150-A072154.

Empirical: G.f. 1 +x*(3 +6*x +11*x^2 +13*x^3 +15*x^4 +15*x^5 +16*x^6 +15*x^7 +15*x^8 +13*x^9 +11*x^10 +6*x^11 +3*x^12) / ( (1+x^2)*(x^6+x^3+1)*(x-1)^2*(1+x+x^2)^2 ) with a(n)= -a(n-2) +a(n-3) +a(n-5) +a(n-9) +a(n-11) -a(n-12) -a(n-14). - R. J. Mathar, Sep 30 2011

More terms from R. J. Mathar, Mar 29 2007

Extended by Joseph Myers, Sep 29 2011

A072150 Coordination sequence for AlPO_4-11 structure with respect to node (Y) where decagon, hexagon and square meet and is adjacent to node of type (X).

Original entry on oeis.org

1, 3, 5, 8, 10, 13, 17, 18, 20, 25, 26, 28, 33, 33, 36, 42, 41, 43, 50, 49, 51, 58, 56, 59, 67, 64, 66, 75, 72, 74, 83, 79, 82, 92, 87, 89, 100, 95, 97, 108, 102, 105, 117, 110, 112, 125, 118, 120, 133, 125, 128, 142, 133, 135, 150, 141, 143, 158, 148, 151

Offset: 0

N. J. A. Sloane, Jun 28 2002

There are three types of nodes in this structure.

The coordination sequence with respect to a particular node gives the number of nodes that can be reached from that node in n steps along edges.

Joseph Myers, Table of n, a(n) for n = 0..1000
M. E. Davis, Ordered porous materials for emerging applications, Nature, 417 (Jun 20 2002), 813-821 (gives structure).
N. J. A. Sloane, AlPO_4-11 structure, after Davis
R. J. Mathar, Illustration of counts and adjacencies (PostScript)

Cf. A072149-A072154.

Empirical: G.f 1 +x*(3+5*x+8*x^2+7*x^3+8*x^4+9*x^5+8*x^6+7*x^7+8*x^8+5*x^9+3*x^10) / ( (x^6+x^3+1)*(x-1)^2*(1+x+x^2)^2 ) with a(n)= +a(n-3) +a(n-9) -a(n-12). - R. J. Mathar, Sep 30 2011

More terms from R. J. Mathar, Mar 29 2007

Extended by Joseph Myers, Sep 29 2011

A068600 Number of n-uniform tilings having n different arrangements of polygons about their vertices.

Original entry on oeis.org

11, 20, 39, 33, 15, 10, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset: 1

Brian Galebach, Mar 28 2002

nonn

Sequence gives the number of edge-to-edge regular-polygon tilings having n topologically distinct vertex types, with each vertex type having a different arrangement of surrounding polygons. Does not allow for tilings with two or more vertex types having the same arrangement of surrounding polygons, even when those vertices are topologically distinct. There are no 8- or higher-uniform tilings having the equivalent number of distinct polygon arrangements.

There are eleven 1-uniform tilings (also called the "Archimedean" tessellations) which comprise the three regular tessellations (all triangles, squares, or hexagons) plus the eight semiregular tessellations. (See A250120. - N. J. A. Sloane, Nov 29 2014)

This sequence was originally calculated by Otto Krotenheerdt.
Branko Grünbaum and G. C. Shephard, Tilings and Patterns. W. H. Freeman, New York, 1987, page 69.
Krotenheerdt, Otto. "Die homogenen Mosaike n-ter Ordnung in der euklidischen Ebene," Wiss. Z. Martin-Luther-Univ. Halle-Wittenberg. Math.-natur. Reihe, 18(1969), 273-290; 19 (1970)19-38 and 97-122.

Steven Dutch, Uniform Tilings
Brian L. Galebach, n-Uniform Tilings
Ng Lay Ling, Honours Project - Tilings and Patterns.

Cf. A068599.

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).

cp's OEIS Frontend

A008579 Coordination sequence for planar net 3.6.3.6. Spherical growth function for a certain reflection group in plane.

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A250122 Coordination sequence for planar net 3.12.12.

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A008706 Coordination sequence for 3.3.3.4.4 planar net.

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A296368 Coordination sequence for the Cairo or dual-3.3.4.3.4 tiling with respect to a trivalent point.

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A298036 Coordination sequence of Dual(4.6.12) tiling with respect to a 12-valent node.

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A298038 Coordination sequence of Dual(4.6.12) tiling with respect to a hexavalent node.

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A298040 Coordination sequence of Dual(4.6.12) tiling with respect to a tetravalent node.

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