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 1-4 of 4 results.

A302655 Number of minimal total dominating sets in the n-path graph.

Original entry on oeis.org

0, 1, 2, 1, 2, 4, 3, 4, 8, 9, 10, 16, 21, 25, 36, 49, 60, 81, 112, 144, 189, 256, 336, 441, 592, 784, 1029, 1369, 1820, 2401, 3182, 4225, 5586, 7396, 9815, 12996, 17200, 22801, 30210, 40000, 53001, 70225, 93000, 123201, 163240, 216225, 286416, 379456, 502665
Offset: 1

Views

Author

Eric W. Weisstein, Apr 11 2018

Keywords

Crossrefs

Row 1 of A303118.

Programs

  • Mathematica
    Table[If[Mod[n, 2] == 0, (RootSum[-1 - # + #^3 &, #^(n/2 + 5) (5 - 6 # + 4 #^2) &]/23)^2, (RootSum[-1 + # - 2 #^2 + #^3 &, #^((n - 1)/2) (4 - 2 # + 5 #^2) &] + RootSum[-1 + #^2 + #^3 &, #^((n - 1)/2) (-5 + 6 # + 3 #^2) &])/23], {n, 50}]
    LinearRecurrence[{0, 0, 1, 1, 1, 1, 0, -1, -1}, {0, 1, 2, 1, 2, 4, 3, 4, 8}, 50]
    CoefficientList[Series[(x (1 + 2 x + x^2 + x^3 + x^4 - x^5 - 2 x^6 - x^7))/(1 - x^3 - x^4 - x^5 - x^6 + x^8 + x^9), {x, 0, 50}], x]
  • PARI
    concat([0],Vec(x^2*(1 + 2*x + x^2 + x^3 + x^4 - x^5 - 2*x^6 - x^7)/(1 - x^3 - x^4 - x^5 - x^6 + x^8 + x^9) + O(x^50))) \\ Andrew Howroyd, Apr 15 2018

Formula

From Andrew Howroyd, Apr 15 2018: (Start)
a(n) = a(n-3) + a(n-4) + a(n-5) + a(n-6) - a(n-8) - a(n-9) for n > 9.
G.f.: x^2*(1 + 2*x + x^2 + x^3 + x^4 - x^5 - 2*x^6 - x^7)/(1 - x^3 - x^4 - x^5 - x^6 + x^8 + x^9).
a(2*n) = A000931(n+5)^2. (End)

Extensions

Terms a(20) and beyond from Andrew Howroyd, Apr 15 2018

A302918 Number of nonequivalent minimal total dominating sets in the n-cycle graph up to rotation.

Original entry on oeis.org

0, 0, 1, 1, 1, 2, 1, 1, 2, 3, 2, 4, 3, 4, 6, 7, 7, 10, 11, 17, 19, 23, 28, 38, 46, 60, 75, 96, 120, 160, 197, 257, 327, 420, 539, 701, 892, 1155, 1488, 1928, 2479, 3220, 4148, 5381, 6961, 9030, 11687, 15183, 19673, 25563, 33174, 43128, 56010, 72864, 94719
Offset: 1

Views

Author

Andrew Howroyd, Apr 15 2018

Keywords

Crossrefs

Cf. A300738.

Programs

  • Mathematica
    A300738 = DifferenceRoot[Function[{f, n}, {f[n] + f[n+1] - f[n+3] - f[n+4] - f[n+5] - f[n+6] + f[n+9] == 0, f[1]==0, f[2]==0, f[3]==3, f[4]==4, f[5]==5, f[6]==9, f[7]==7, f[8]==4, f[9]==12}]];
    a[n_] := (1/n) Sum[EulerPhi[n/d] A300738[d], {d, Divisors[n]}];
    a /@ Range[1, 55] (* Jean-François Alcover, Sep 21 2019 *)
  • PARI
    NecklaceT(v)={vector(#v, n, sumdiv(n,d,eulerphi(n/d)*v[d])/n)}
    NecklaceT(concat([0,0],Vec((3 + 4*x + 5*x^2 + 6*x^3 - 8*x^5 - 9*x^6)/((1 - x^2 - x^3)*(1 + x^2 - x^6)) + O(x^50))))

Formula

a(n) = (1/n) * Sum_{d|n} phi(n/d) * A300738(d).

A362812 Number of minimal total dominating sets in the n-double cone graph.

Original entry on oeis.org

15, 24, 35, 93, 63, 32, 162, 645, 506, 649, 1547, 2429, 4654, 10032, 14195, 20772, 43719, 83561, 134731, 234300, 414782, 707329, 1276950, 2313493, 3932343, 6765257, 12110458, 21381436, 37295511, 65610064, 114854155, 200533989, 353703319, 623201368
Offset: 3

Views

Author

Eric W. Weisstein, May 04 2023

Keywords

Crossrefs

Formula

a(n) = 2*n + A300738(n)^2. - Andrew Howroyd, May 04 2023

Extensions

Terms a(13) and beyond from Andrew Howroyd, May 04 2023

A302658 Number of minimal total dominating sets in the wheel graph on n nodes.

Original entry on oeis.org

1, 2, 6, 8, 10, 15, 14, 12, 21, 35, 33, 37, 52, 63, 83, 116, 136, 162, 228, 309, 388, 506, 667, 865, 1155, 1547, 2010, 2629, 3509, 4654, 6138, 8132, 10750, 14195, 18842, 25000, 33041, 43719, 57957, 76769, 101680, 134731, 178407, 236240, 313052, 414782, 549336
Offset: 2

Views

Author

Eric W. Weisstein, Apr 11 2018

Keywords

Comments

Wheel graphs are defined for n>=4; extended to n=2 using formula. - Andrew Howroyd, Apr 15 2018

Crossrefs

Programs

  • Mathematica
    Table[n - 1 + RootSum[-1 - # + #^3 &, #^(n - 1) &] + (1 - (-1)^n) RootSum[-1 + #^2 + #^3 &, #^((n - 1)/2) &], {n, 2, 50}]
    LinearRecurrence[{2, -1, 1, -1, 0, 0, -1, 0, 1, 1, -1}, {1, 2, 6, 8, 10, 15, 14, 12, 21, 35, 33}, 50]
    CoefficientList[Series[(1 + 3 x^2 - 3 x^3 - x^4 - x^5 - 8 x^6 - 2 x^7 + 8 x^8 + 11 x^9 - 9 x^10)/((-1 + x)^2 (1 - x^3 - x^4 - x^5 - x^6 + x^8 + x^9)), {x, 0, 50}], x]
  • PARI
    {my(v=concat([0,0],Vec((3 + 4*x + 5*x^2 + 6*x^3 - 8*x^5 - 9*x^6)/((1 - x^2 - x^3)*(1 + x^2 - x^6)) + O(x^50))));vector(#v,i,v[i]+i)} \\ Andrew Howroyd, Apr 15 2018

Formula

a(n) = A300738(n-1) + (n-1). - Andrew Howroyd, Apr 15 2018
G.f.: x^2*(1 + 3*x^2 - 3*x^3 - x^4 - x^5 - 8*x^6 - 2*x^7 + 8*x^8 + 11*x^9 - 9*x^10)/((-1 + x)^2*(1 - x^3 - x^4 - x^5 - x^6 + x^8 + x^9)).

Extensions

a(2)-a(3) and terms a(20) and beyond from Andrew Howroyd, Apr 15 2018
Showing 1-4 of 4 results.