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 1-6 of 6 results.

A264236 Number of vertices at level n of the hyperbolic Pascal pyramid.

Original entry on oeis.org

1, 3, 6, 13, 36, 138, 736, 4908, 36351, 280228, 2190651, 17206203, 135357481, 1065387963, 8387050686, 66029196613, 519841755036, 4092692363058, 32221664474776, 253680537891828, 1997222414704551, 15724098193422028, 123795561597659331, 974640390569138163
Offset: 0

Views

Author

Michel Marcus, Nov 09 2015

Keywords

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{12, -37, 37, -12, 1}, {1, 3, 6, 13, 36}, 30] (* Bruno Berselli, Nov 09 2015 *)
  • PARI
    Vec((1-9*x+7*x^2+15*x^3+3*x^4)/((1-x)*(1-3*x+x^2)*(1-8*x+x^2)) + O(x^50)) \\ Altug Alkan, Nov 09 2015

Formula

a(n) = 12*a(n-1) - 37*a(n-2) + 37*a(n-3) - 12*a(n-4) + a(n-5).
a(n) = (-3/2 + 9*sqrt(5)/10)*((3 + sqrt(5))/2)^n + (-3/2 - 9*sqrt(5)/10)*((3 - sqrt(5))/2)^n + (7/12 - 3*sqrt(15)/20)*(4 + sqrt(15))^n + (7/12 + 3*sqrt(15)/20)*(4 - sqrt(15))^n + 17/6. (See Németh paper, page 9.)
G.f.: (1 - 9*x + 7*x^2 + 15*x^3 + 3*x^4)/((1 - x)*(1 - 3*x + x^2)*(1 - 8*x + x^2)). [Bruno Berselli, Nov 09 2015]
a(n) = A076765(n-3) + 3*Fibonacci(2*(n-1)) + 3. - Ehren Metcalfe, Apr 18 2019

Extensions

More terms from Bruno Berselli, Nov 09 2015

A292295 Sum of values of vertices of type A at level n of the hyperbolic Pascal pyramid.

Original entry on oeis.org

0, 0, 6, 18, 54, 174, 582, 1974, 6726, 22950, 78342, 267462, 913158, 3117702, 10644486, 36342534, 124081158, 423639558, 1446395910, 4938304518, 16860426246, 57565095942, 196539531270, 671027933190, 2291032670214, 7822074814470, 26706233917446, 91180786040838
Offset: 0

Views

Author

Eric M. Schmidt, Sep 13 2017

Keywords

Crossrefs

Cf. A264237.

Programs

  • Mathematica
    CoefficientList[Series[6*x^2*(1 - 2*x)/((1 - x)*(1 - 4*x + 2*x^2)), {x, 0, 30}], x] (* Wesley Ivan Hurt, Sep 17 2017 *)
  • PARI
    concat(vector(2), Vec(6*x^2*(1 - 2*x) / ((1 - x)*(1 - 4*x + 2*x^2)) + O(x^30))) \\ Colin Barker, Sep 17 2017

Formula

a(n) = 5*a(n-1) - 6*a(n-2) + 2*a(n-3), n >= 4.
From Colin Barker, Sep 17 2017: (Start)
G.f.: 6*x^2*(1 - 2*x) / ((1 - x)*(1 - 4*x + 2*x^2)).
a(n) = (-3/2)*(-4 + (4-3*sqrt(2))*(2+sqrt(2))^n + (2-sqrt(2))^n*(4+3*sqrt(2))) for n>0.
(End)

A292296 Sum of values of vertices of type B at level n of the hyperbolic Pascal pyramid.

Original entry on oeis.org

0, 0, 0, 6, 30, 114, 402, 1386, 4746, 16218, 55386, 189114, 645690, 2204538, 7526778, 25698042, 87738618, 299558394, 1022756346, 3491908602, 11922121722, 40704669690, 138974435322, 474488401914, 1620004737018, 5531042144250, 18884159102970, 64474552123386
Offset: 0

Views

Author

Eric M. Schmidt, Sep 14 2017

Keywords

Crossrefs

Cf. A264237.

Programs

  • Mathematica
    CoefficientList[Series[6*x^3/((1 - x)*(1 - 4*x + 2*x^2)), {x, 0, 30}],
    x] (* Wesley Ivan Hurt, Sep 17 2017 *)
  • PARI
    concat(vector(3), Vec(6*x^3 / ((1 - x)*(1 - 4*x + 2*x^2)) + O(x^30))) \\ Colin Barker, Sep 17 2017

Formula

a(n) = 5*a(n-1) - 6*a(n-2) + 2*a(n-3), n >= 4.
From Colin Barker, Sep 17 2017: (Start)
G.f.: 6*x^3 / ((1 - x)*(1 - 4*x + 2*x^2)).
a(n) = (1/2)*(-12 + (9-6*sqrt(2))*(2+sqrt(2))^n + (2-sqrt(2))^n*(9+6*sqrt(2))) for n>0.
(End)

A292297 Sum of values of vertices of type C at level n of the hyperbolic Pascal pyramid.

Original entry on oeis.org

0, 0, 0, 6, 36, 210, 1452, 12138, 114684, 1147002, 11729148, 120902202, 1249686492, 12929303130, 133809210108, 1384977143610, 14335551770268, 148385432561562, 1535924231893308, 15898233466089210, 164561459781232092, 1703363953470584922, 17631399812695032444
Offset: 0

Views

Author

Eric M. Schmidt, Sep 14 2017

Keywords

Crossrefs

Cf. A264237.

Programs

  • Mathematica
    CoefficientList[Series[6*x^3*(1 - 12*x + 26*x^2 - 20*x^3)/((1 - x)*(1 - 4*x + 2*x^2)*(1 - 13*x + 28*x^2 - 6*x^3)), {x, 0, 20}], x] (* Wesley Ivan Hurt, Sep 17 2017 *)
  • PARI
    concat(vector(3), Vec(6*x^3*(1 - 12*x + 26*x^2 - 20*x^3) / ((1 - x)*(1 - 4*x + 2*x^2)*(1 - 13*x + 28*x^2 - 6*x^3)) + O(x^30))) \\ Colin Barker, Sep 17 2017

Formula

a(n) = 18*a(n-1) - 99*a(n-2) + 226*a(n-3) - 224*a(n-4) + 92*a(n-5) - 12*a(n-6), n >= 7.
G.f.: 6*x^3*(1 - 12*x + 26*x^2 - 20*x^3) / ((1 - x)*(1 - 4*x + 2*x^2)*(1 - 13*x + 28*x^2 - 6*x^3)). - Colin Barker, Sep 17 2017

A292298 Sum of values of vertices of type D at level n of the hyperbolic Pascal pyramid.

Original entry on oeis.org

0, 0, 0, 0, 24, 324, 3600, 38148, 398112, 4132596, 42818208, 443356212, 4589665248, 47509091508, 491769434400, 5090291998452, 52689326584800, 545383755284532, 5645229662006688, 58433377222329972, 604839778633231200, 6260653947359090868, 64803587809297981728
Offset: 0

Views

Author

Eric M. Schmidt, Sep 14 2017

Keywords

Crossrefs

Cf. A264237.

Programs

  • Magma
    I:=[0,0,0,0,24,324,3600]; [n le 7 select I[n] else 18*Self(n-1)-99*Self(n-2)+226*Self(n-3)-224*Self(n-4)+ 92*Self(n-5)-12*Self(n-6): n in [1..30]]; // Vincenzo Librandi, Sep 17 2017
    
  • Mathematica
    Join[{0}, LinearRecurrence[{18, -99, 226, -224, 92, -12}, {0, 0, 0, 24, 324, 3600}, 20] ] (* Vincenzo Librandi, Sep 17 2017 *)
    CoefficientList[Series[12*x^4*(2 - 9*x + 12*x^2)/((1 - x)*(1 - 4*x + 2*x^2)*(1 - 13*x + 28*x^2 - 6*x^3)), {x, 0, 20}], x] (* Wesley Ivan Hurt, Sep 17 2017 *)
  • PARI
    concat(vector(4), Vec(12*x^4*(2 - 9*x + 12*x^2) / ((1 - x)*(1 - 4*x + 2*x^2)*(1 - 13*x + 28*x^2 - 6*x^3)) + O(x^30))) \\ Colin Barker, Sep 17 2017

Formula

a(n) = 18*a(n-1) - 99*a(n-2) + 226*a(n-3) - 224*a(n-4) + 92*a(n-5) - 12*a(n-6), n >= 7.
G.f.: 12*x^4*(2 - 9*x + 12*x^2) / ((1 - x)*(1 - 4*x + 2*x^2)*(1 - 13*x + 28*x^2 - 6*x^3)). - Colin Barker, Sep 17 2017

A292299 Sum of values of vertices of type E at level n of the hyperbolic Pascal pyramid.

Original entry on oeis.org

0, 0, 0, 0, 18, 312, 3798, 41544, 438270, 4566120, 47368110, 490668936, 5080145070, 52588590888, 544355820750, 5634640292424, 58323941179182, 603707608725096, 6248936971173390, 64682313170747016, 669522088312069614, 6930176023749038760, 71733763792342350798
Offset: 0

Views

Author

Eric M. Schmidt, Sep 14 2017

Keywords

Crossrefs

Cf. A264237.

Programs

  • Mathematica
    CoefficientList[Series[6*x^4*(3 - 2*x - 6*x^2)/((1 - x)*(1 - 4*x + 2*x^2)*(1 - 13*x + 28*x^2 - 6*x^3)), {x, 0, 20}], x] (* Wesley Ivan Hurt, Sep 17 2017 *)
  • PARI
    concat(vector(4), Vec(6*x^4*(3 - 2*x - 6*x^2) / ((1 - x)*(1 - 4*x + 2*x^2)*(1 - 13*x + 28*x^2 - 6*x^3)) + O(x^30))) \\ Colin Barker, Sep 17 2017

Formula

a(n) = 18*a(n-1) - 99*a(n-2) + 226*a(n-3) - 224*a(n-4) + 92*a(n-5) - 12*a(n-6), n >= 7.
G.f.: 6*x^4*(3 - 2*x - 6*x^2) / ((1 - x)*(1 - 4*x + 2*x^2)*(1 - 13*x + 28*x^2 - 6*x^3)). - Colin Barker, Sep 17 2017
Showing 1-6 of 6 results.