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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A265069 Coordination sequence for (2,6,6) tiling of hyperbolic plane.

Original entry on oeis.org

1, 3, 5, 8, 13, 21, 32, 47, 71, 108, 163, 245, 368, 555, 837, 1260, 1897, 2857, 4304, 6483, 9763, 14704, 22147, 33357, 50240, 75667, 113965, 171648, 258525, 389373, 586448, 883271, 1330327, 2003652, 3017771, 4545173, 6845648, 10310475, 15528973, 23388740, 35226617, 53056065, 79909632, 120354747, 181270579, 273018088
Offset: 0

Views

Author

N. J. A. Sloane, Dec 29 2015

Keywords

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[(x^5 + x^4 + x^3 + x^2 + x + 1) (x + 1)/(x^6 - x^5 - x^3 - x + 1), {x, 0, 60}], x] (* Vincenzo Librandi, Dec 30 2015 *)
  • PARI
    Vec((x^5+x^4+x^3+x^2+x+1)*(x+1)/(x^6-x^5-x^3-x+1) + O(x^50)) \\ Michel Marcus, Dec 30 2015

Formula

G.f.: (x^5+x^4+x^3+x^2+x+1)*(x+1)/(x^6-x^5-x^3-x+1).

A265070 Coordination sequence for (2,6,infinity) tiling of hyperbolic plane.

Original entry on oeis.org

1, 3, 5, 8, 13, 21, 33, 51, 80, 126, 198, 311, 488, 766, 1203, 1889, 2966, 4657, 7312, 11481, 18027, 28305, 44443, 69782, 109568, 172038, 270125, 424136, 665956, 1045649, 1641823, 2577904, 4047689, 6355468, 9979021, 15668533, 24601905, 38628615, 60652616, 95233542, 149530690, 234785211, 368647368, 578830674
Offset: 0

Views

Author

N. J. A. Sloane, Dec 29 2015

Keywords

Crossrefs

Programs

  • Magma
    I:=[1,3,5,8,13,21,33]; [n le 7 select I[n] else Self(n-1)+Self(n-3)+Self(n-5): n in [1..50]]; // Vincenzo Librandi, Dec 30 2015
    
  • Mathematica
    CoefficientList[Series[-(x^5 + x^4 + x^3 + x^2 + x + 1) (x + 1)/(x^5 + x^3 + x - 1), {x, 0, 60}], x] (* Vincenzo Librandi, Dec 30 2015 *)
  • PARI
    x='x+O('x^50); Vec((x+1)*(x^5+x^4+x^3+x^2+x+1)/(1-x-x^3-x^5)) \\ G. C. Greubel, Aug 07 2017

Formula

G.f.: -(x^5+x^4+x^3+x^2+x+1)*(x+1)/(x^5+x^3+x-1).
a(n) = a(n-1)+a(n-3)+a(n-5) for n>6. - Vincenzo Librandi, Dec 30 2015

A265071 Coordination sequence for (3,3,4) tiling of hyperbolic plane.

Original entry on oeis.org

1, 3, 6, 10, 15, 22, 31, 44, 62, 87, 122, 171, 240, 336, 471, 660, 925, 1296, 1816, 2545, 3566, 4997, 7002, 9812, 13749, 19266, 26997, 37830, 53010, 74281, 104088, 145855, 204382, 286394, 401315, 562350, 788003, 1104204, 1547286, 2168163, 3038178, 4257303, 5965624, 8359440, 11713819, 16414204, 23000705, 32230160
Offset: 0

Views

Author

N. J. A. Sloane, Dec 29 2015

Keywords

Crossrefs

Programs

  • Magma
    I:=[1,3,6,10,15,22,31]; [n le 7 select I[n] else Self(n-2)+Self(n-3)+Self(n-4)- Self(n-6): n in [1..50]]; // Vincenzo Librandi, Dec 30 2015
    
  • Mathematica
    CoefficientList[Series[(x^3 + x^2 + x + 1) (x^2 + x + 1) (x + 1)/(x^6 - x^4 - x^3 - x^2 + 1), {x, 0, 60}], x] (* Vincenzo Librandi, Dec 30 2015 *)
  • PARI
    x='x+O('x^50); Vec((x^3+x^2+x+1)*(x^2+x+1)*(x+1)/(x^6-x^4-x^3-x^2+1)) \\ G. C. Greubel, Aug 07 2017

Formula

G.f.: (x^3+x^2+x+1)*(x^2+x+1)*(x+1)/(x^6-x^4-x^3-x^2+1).
a(n) = a(n-2)+a(n-3)+a(n-4)-a(n-6) for n>6. - Vincenzo Librandi, Dec 30 2015

A265072 Coordination sequence for (3,3,5) tiling of hyperbolic plane.

Original entry on oeis.org

1, 3, 6, 10, 16, 25, 38, 57, 86, 130, 196, 295, 444, 669, 1008, 1518, 2286, 3443, 5186, 7811, 11764, 17718, 26686, 40193, 60536, 91175, 137322, 206826, 311508, 469173, 706638, 1064293, 1602970, 2414290, 3636248, 5476683, 8248628, 12423553, 18711556, 28182142, 42446130, 63929631, 96286698, 145020831, 218421048
Offset: 0

Views

Author

N. J. A. Sloane, Dec 29 2015

Keywords

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[(x^2 + x + 1) (x^4 + x^3 + x^2 + x + 1)/(x^6 - x^5 - x^3 - x + 1), {x, 0, 60}], x] (* Vincenzo Librandi, Dec 30 2015 *)
    LinearRecurrence[{1,0,1,0,1,-1},{1,3,6,10,16,25,38},50] (* Harvey P. Dale, Oct 07 2022 *)
  • PARI
    x='x+O('x^50); Vec((x^2+x+1)*(x^4+x^3+x^2+x+1)/(x^6-x^5-x^3-x+1)) \\ G. C. Greubel, Aug 07 2017

Formula

G.f.: (x^2+x+1)*(x^4+x^3+x^2+x+1)/(x^6-x^5-x^3-x+1).

A265073 Coordination sequence for (3,3,6) tiling of hyperbolic plane.

Original entry on oeis.org

1, 3, 6, 10, 16, 26, 41, 64, 99, 154, 240, 374, 582, 905, 1408, 2191, 3410, 5306, 8256, 12846, 19989, 31104, 48399, 75310, 117184, 182342, 283730, 441493, 686976, 1068955, 1663326, 2588186, 4027296, 6266594, 9751009, 15172864, 23609435, 36736994, 57163872, 88948710, 138406878, 215365281, 335114880, 521448871
Offset: 0

Views

Author

N. J. A. Sloane, Dec 29 2015

Keywords

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[(x^3 + 1) (x^2 + x + 1) (x + 1)/(x^6 - x^5 - x^4 + x^3 - x^2 - x + 1), {x, 0, 60}], x] (* Vincenzo Librandi, Dec 30 2015 *)
  • PARI
    x='x+O('x^50); Vec((x^3+1)*(x^2+x+1)*(x+1)/(x^6-x^5-x^4+x^3-x^2-x+1)) \\ G. C. Greubel, Aug 07 2017

Formula

G.f.: (x^3+1)*(x^2+x+1)*(x+1)/(x^6-x^5-x^4+x^3-x^2-x+1).

A265074 Coordination sequence for (3,3,7) tiling of hyperbolic plane.

Original entry on oeis.org

1, 3, 6, 10, 16, 26, 42, 67, 106, 167, 264, 418, 662, 1048, 1658, 2623, 4150, 6567, 10392, 16444, 26020, 41172, 65148, 103087, 163120, 258113, 408424, 646268, 1022620, 1618140, 2560460, 4051537, 6410938, 10144329, 16051850, 25399600, 40190986, 63596094, 100631100, 159233337, 251962422, 398692029, 630869210
Offset: 0

Views

Author

N. J. A. Sloane, Dec 29 2015

Keywords

Crossrefs

Programs

  • Magma
    I:=[1,3,6,10,16,26,42,67,106]; [n le 9 select I[n] else Self(n-1)+Self(n-3)+Self(n-5)+Self(n-7)-Self(n-8): n in [1..50]]; // Vincenzo Librandi, Dec 30 2015
    
  • Mathematica
    CoefficientList[Series[(x^2 + x + 1) (x^6 + x^5 + x^4 + x^3 + x^2 + x + 1)/(x^8 - x^7 - x^5 - x^3 - x + 1), {x, 0, 60}], x] (* Vincenzo Librandi, Dec 30 2015 *)
  • PARI
    x='x+O('x^50); Vec((x^2+x+1)*(x^6+x^5+x^4+x^3+x^2+x+1)/(x^8-x^7-x^5-x^3-x+1)) \\ G. C. Greubel, Aug 07 2017

Formula

G.f.: (x^2+x+1)*(x^6+x^5+x^4+x^3+x^2+x+1)/(x^8-x^7-x^5-x^3-x+1).
a(n) = a(n-1)+a(n-3)+a(n-5)+a(n-7)-a(n-8) for n>8. - Vincenzo Librandi, Dec 30 2015

A265075 Coordination sequence for (3,4,4) tiling of hyperbolic plane.

Original entry on oeis.org

1, 3, 6, 11, 18, 29, 46, 73, 116, 183, 290, 459, 726, 1149, 1818, 2877, 4552, 7203, 11398, 18035, 28538, 45157, 71454, 113065, 178908, 283095, 447954, 708819, 1121598, 1774757, 2808282, 4443677, 7031440, 11126179, 17605478, 27857979, 44080994, 69751437, 110370990, 174645225, 276349380, 437280663, 691929826
Offset: 0

Views

Author

N. J. A. Sloane, Dec 29 2015

Keywords

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[(x^3 + x^2 + x + 1) (x^2 + x + 1) (x + 1)/(x^6 - x^4 - 2 x^3 - x^2 + 1), {x, 0, 60}], x] (* Vincenzo Librandi, Dec 30 2015 *)
  • PARI
    x='x+O('x^50); Vec((x^3+x^2+x+1)*(x^2+x+1)*(x+1)/(x^6-x^4-2*x^3-x^2+1)) \\ G. C. Greubel, Aug 07 2017

Formula

G.f.: (x^3+x^2+x+1)*(x^2+x+1)*(x+1)/(x^6-x^4-2*x^3-x^2+1).

A265076 Coordination sequence for (3,5,5) tiling of hyperbolic plane.

Original entry on oeis.org

1, 3, 6, 11, 20, 35, 60, 103, 178, 307, 528, 909, 1566, 2697, 4644, 7997, 13772, 23717, 40842, 70333, 121120, 208579, 359190, 618555, 1065204, 1834371, 3158940, 5439959, 9368066, 16132595, 27781680, 47842381, 82388590, 141880057, 244329348, 420755613, 724576428, 1247781333, 2148784026, 3700386173, 6372375104
Offset: 0

Views

Author

N. J. A. Sloane, Dec 29 2015

Keywords

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[(x^2 + x + 1) (x^4 + x^3 + x^2 + x + 1)/(x^6 - x^5 - 2 x^3 - x + 1), {x, 0, 60}], x] (* Vincenzo Librandi, Dec 30 2015 *)
  • PARI
    Vec((x^2+x+1)*(x^4+x^3+x^2+x+1)/(x^6-x^5-2*x^3-x+1) + O(x^50)) \\ Michel Marcus, Dec 30 2015

Formula

G.f.: (x^2+x+1)*(x^4+x^3+x^2+x+1)/(x^6-x^5-2*x^3-x+1).

A265077 Coordination sequence for (3,6,8) tiling of hyperbolic plane.

Original entry on oeis.org

1, 3, 6, 11, 20, 37, 66, 117, 208, 371, 662, 1179, 2100, 3741, 6666, 11877, 21160, 37699, 67166, 119667, 213204, 379853, 676762, 1205749, 2148216, 3827355, 6818982, 12148995, 21645180, 38563997, 68707298, 122411917, 218094408, 388566507, 692287030, 1233408755, 2197494812, 3915152565, 6975406506, 12427688349
Offset: 0

Views

Author

N. J. A. Sloane, Dec 29 2015

Keywords

Crossrefs

Programs

  • Magma
    I:=[1,3,6,11,20,37,66]; [n le 7 select I[n] else Self(n-1)+Self(n-2)+Self(n-4) + Self(n-5)-Self(n-6): n in [1..50]]; // Vincenzo Librandi, Dec 30 2015
  • Mathematica
    CoefficientList[Series[(x^5 + x^4 + x^3 + x^2 + x + 1) (x + 1)/(x^6 - x^5 - x^4 - x^2 - x + 1), {x, 0, 60}], x] (* Vincenzo Librandi, Dec 30 2015 *)
  • PARI
    Vec((x^5+x^4+x^3+x^2+x+1)*(x+1)/(x^6-x^5-x^4-x^2-x+1) + O(x^50)) \\ Michel Marcus, Dec 30 2015
    

Formula

G.f.: (x^5+x^4+x^3+x^2+x+1)*(x+1)/(x^6-x^5-x^4-x^2-x+1).
a(n) = a(n-1)+a(n-2)+a(n-4)+a(n-5)-a(n-6) for n>6. - Vincenzo Librandi, Dec 30 2015

A054888 Layer counting sequence for hyperbolic tessellation by regular pentagons of angle Pi/2.

Original entry on oeis.org

1, 5, 15, 40, 105, 275, 720, 1885, 4935, 12920, 33825, 88555, 231840, 606965, 1589055, 4160200, 10891545, 28514435, 74651760, 195440845, 511670775, 1339571480, 3507043665, 9181559515, 24037634880, 62931345125
Offset: 0

Views

Author

Paolo Dominici (pl.dm(AT)libero.it), May 23 2000

Keywords

Comments

The layer sequence is the sequence of the cardinalities of the layers accumulating around a (finite-sided) polygon of the tessellation under successive side-reflections.

Crossrefs

Programs

  • Haskell
    a054888 n = a054888_list !! (n-1)
    a054888_list = 1 : zipWith (+) (tail a002878_list) a002878_list
    -- Reinhard Zumkeller, Jan 11 2012
    
  • Magma
    [n eq 0 select 1 else 5*Fibonacci(2*n): n in [0..40]]; // G. C. Greubel, Feb 08 2023
    
  • Mathematica
    LinearRecurrence[{3,-1},{1,5,15},30] (* Harvey P. Dale, Jan 15 2023 *)
    Join[{1}, 5*Fibonacci[2*Range[40]]] (* G. C. Greubel, Feb 08 2023 *)
  • PARI
    {a(n)=polcoeff(exp(sum(k=1,n,5*fibonacci(k)^2*x^k/k)+x*O(x^n)), n)} /* Paul D. Hanna, Feb 21 2012 */
    
  • SageMath
    [5*fibonacci(2*n) + int(n==0) for n in range (41)] # G. C. Greubel, Feb 08 2023

Formula

a(n) = 5*A001906(n) + [n=0].
G.f.: (1+x)^2/(1-3*x+x^2).
G.f.: exp( Sum_{n>=1} 5*Fibonacci(n)^2 * x^n/n ). - Paul D. Hanna, Feb 21 2012
a(n) = A001906(n-1) + 2*A001906(n) + A001906(n+1). - R. J. Mathar, Nov 28 2011
a(n) = A203976(A004277(n-1)). - Reinhard Zumkeller, Jan 11 2012
a(n) = 5*A000045(2*n) for n >= 1. - Robert Israel, Jun 01 2015
a(n) = A002878(n-1)+A002878(n). - R. J. Mathar, Jul 09 2024

Extensions

Offset changed to 0 by N. J. A. Sloane, Jan 03 2022 at the suggestion of Michel Marcus
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