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 1-2 of 2 results.

A300738 Number of minimal total dominating sets in the n-cycle graph.

Original entry on oeis.org

0, 0, 3, 4, 5, 9, 7, 4, 12, 25, 22, 25, 39, 49, 68, 100, 119, 144, 209, 289, 367, 484, 644, 841, 1130, 1521, 1983, 2601, 3480, 4624, 6107, 8100, 10717, 14161, 18807, 24964, 33004, 43681, 57918, 76729, 101639, 134689, 178364, 236196, 313007, 414736, 549289
Offset: 1

Views

Author

Andrew Howroyd, Apr 15 2018

Keywords

Crossrefs

Cf. A001608, A001638 (total dominating sets), A253413, A302653, A302655, A302918.

Programs

  • Mathematica
    Table[RootSum[-1 - # + #^3 &, #^n &] + (1 + (-1)^n) RootSum[-1 + #^2 + #^3 &, #^(n/2) &], {n, 20}]
    Perrin[n_] := RootSum[-1 - # + #^3 &, #^n &]; Table[With[{b = Mod[n, 2, 1]}, Perrin[n/b]^b], {n, 20}]
    LinearRecurrence[{0, 0, 1, 1, 1, 1, 0, -1, -1}, {0, 0, 3, 4, 5, 9, 7, 4, 12}, 20]
    CoefficientList[Series[x^2 (3 + 4 x + 5 x^2 + 6 x^3 - 8 x^5 - 9 x^6)/(1 - x^3 - x^4 - x^5 - x^6 + x^8 + x^9), {x, 0, 20}], x]
  • PARI
    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) = a(n-3) + a(n-4) + a(n-5) + a(n-6) - a(n-8) - a(n-9) for n > 9.
G.f.: x^3*(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)).
a(2*n) = A001608(n)^2.
a(2*n-1) = A001608(2*n-1), where A001608 are the Perrin numbers.

A302654 Number of minimum total dominating sets in the n-path graph.

Original entry on oeis.org

0, 1, 2, 1, 1, 4, 3, 1, 2, 9, 4, 1, 3, 16, 5, 1, 4, 25, 6, 1, 5, 36, 7, 1, 6, 49, 8, 1, 7, 64, 9, 1, 8, 81, 10, 1, 9, 100, 11, 1, 10, 121, 12, 1, 11, 144, 13, 1, 12, 169, 14, 1, 13, 196, 15, 1, 14, 225, 16, 1, 15, 256, 17, 1, 16, 289, 18, 1, 17, 324, 19, 1, 18, 361, 20, 1
Offset: 1

Views

Author

Eric W. Weisstein, Apr 11 2018

Keywords

Crossrefs

Row 1 of A303293.

Programs

  • Mathematica
    Table[Piecewise[{{1, Mod[n, 4] == 0}, {((n + 2)/4)^2, Mod[n, 4] == 2}, {(n - 1)/4, Mod[n, 4] == 1}, {(n + 5)/4, Mod[n, 4] == 3}}], {n, 20}]
    Table[((-1)^n (n - 2)^2 + (6 + n)^2 - 2 (n - 2) (n + 6) Cos[n Pi/2] - 48 Sin[n Pi/2])/64, {n, 20}]
    LinearRecurrence[{0, 0, 0, 3, 0, 0, 0, -3, 0, 0, 0, 1}, {0, 1, 2, 1, 1, 4, 3, 1, 2, 9, 4, 1}, 20]
  • PARI
    concat(0, Vec(x^2*(1 + 2*x + x^2 + x^3 + x^4 - 3*x^5 - 2*x^6 - x^7 + x^9 + x^10) / ((1 - x)^3*(1 + x)^3*(1 + x^2)^3) + O(x^70))) \\ Colin Barker, Dec 25 2019

Formula

a(n) = ((-1)^n*(n - 2)^2 + (6 + n)^2 - 2*(n - 2)*(n + 6)*cos(n*Pi/2) - 48*sin(n*Pi/2))/6.
a(n) = 3*a(n-4) - 3*a(n-8) + a(n-12).
G.f.: x^2*(1 + 2*x + x^2 + x^3 + x^4 - 3*x^5 - 2*x^6 - x^7 + x^9 + x^10) / ((1 - x)^3*(1 + x)^3*(1 + x^2)^3). - Colin Barker, Dec 25 2019
E.g.f.: ((12 + x^2)*cos(x) + (20 + 8*x + x^2)*cosh(x) + (5*x - 24)*sin(x) + (16 + 5*x)*sinh(x) - 32)/32. - Stefano Spezia, Jun 10 2025
Showing 1-2 of 2 results.