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 1-7 of 7 results.

A350820 Array read by antidiagonals: T(m,n) is the number of minimum dominating sets in the grid graph P_m X P_n.

Original entry on oeis.org

1, 2, 2, 1, 6, 1, 4, 3, 3, 4, 3, 12, 10, 12, 3, 1, 2, 29, 29, 2, 1, 8, 17, 1, 2, 1, 17, 8, 4, 2, 2, 52, 52, 2, 2, 4, 1, 20, 11, 92, 22, 92, 11, 20, 1, 13, 2, 46, 2, 13, 13, 2, 46, 2, 13, 5, 24, 1, 4, 3, 288, 3, 4, 1, 24, 5, 1, 2, 3, 324, 344, 34, 34, 344, 324, 3, 2, 1
Offset: 1

Views

Author

Andrew Howroyd, Jan 17 2022

Keywords

Comments

The domination number of the grid graphs is tabulated in A350823.

Examples

			Table begins:
===================================
m\n | 1  2  3  4   5   6  7   8
----+------------------------------
  1 | 1  2  1  4   3   1  8   4 ...
  2 | 2  6  3 12   2  17  2  20 ...
  3 | 1  3 10 29   1   2 11  46 ...
  4 | 4 12 29  2  52  92  2   4 ...
  5 | 3  2  1 52  22  13  3 344 ...
  6 | 1 17  2 92  13 288 34   2 ...
  7 | 8  2 11  2   3  34  2  34 ...
  8 | 4 20 46  4 344   2 34  52 ...
  ...
		

Crossrefs

Rows 1..4 are A347633, A347558, A350821, A350822.
Main diagonal is A347632.
Cf. A218354 (dominating sets), A286847 (minimal dominating sets), A303293, A350815, A350823.

Formula

T(m,n) = T(n,m).

A303118 Array read by antidiagonals: T(m,n) = number of minimal total dominating sets in the grid graph P_m X P_n.

Original entry on oeis.org

0, 1, 1, 2, 4, 2, 1, 4, 4, 1, 2, 16, 6, 16, 2, 4, 16, 49, 49, 16, 4, 3, 49, 66, 169, 66, 49, 3, 4, 81, 225, 576, 576, 225, 81, 4, 8, 169, 640, 2601, 2622, 2601, 640, 169, 8, 9, 324, 1681, 10000, 14400, 14400, 10000, 1681, 324, 9, 10, 625, 4641, 38416, 81055, 137641, 81055, 38416, 4641, 625, 10
Offset: 1

Views

Author

Andrew Howroyd, Apr 18 2018

Keywords

Examples

			Table begins:
=============================================================
m\n| 1   2    3     4      5       6         7          8
---+---------------------------------------------------------
1  | 0   1    2     1      2       4         3          4 ...
2  | 1   4    4    16     16      49        81        169 ...
3  | 2   4    6    49     66     225       640       1681 ...
4  | 1  16   49   169    576    2601     10000      38416 ...
5  | 2  16   66   576   2622   14400     81055     440896 ...
6  | 4  49  225  2601  14400  137641   1081600    8185321 ...
7  | 3  81  640 10000  81055 1081600  11458758  125955729 ...
8  | 4 169 1681 38416 440896 8185321 125955729 1944369025 ...
...
		

Crossrefs

Rows 1..2 are A302655, A303072.
Main diagonal is A303161.

A300358 Array read by antidiagonals: T(m,n) = total domination number of the grid graph P_m X P_n.

Original entry on oeis.org

1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 4, 3, 4, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 6, 5, 4, 4, 4, 6, 6, 8, 8, 6, 6, 4, 5, 6, 7, 8, 9, 8, 7, 6, 5, 6, 6, 8, 10, 10, 10, 10, 8, 6, 6, 6, 8, 9, 12, 12, 12, 12, 12, 9, 8, 6, 6, 8, 10, 12, 14, 14, 14, 14, 12, 10, 8, 6, 7, 8, 11, 14, 15, 16, 15, 16, 15, 14, 11, 8, 7
Offset: 1

Views

Author

Andrew Howroyd, Apr 20 2018

Keywords

Examples

			Table begins:
=======================================================
m\n| 1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16
---+---------------------------------------------------
1  | 1  2  2  2  3  4  4  4  5  6  6  6  7  8  8  8 ...
2  | 2  2  2  4  4  4  6  6  6  8  8  8 10 10 10 12 ...
3  | 2  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 ...
4  | 2  4  4  6  8  8 10 12 12 14 14 16 18 18 20 20 ...
5  | 3  4  5  8  9 10 12 14 15 16 18 20 21 22 24 26 ...
6  | 4  4  6  8 10 12 14 16 18 20 20 24 24 26 28 30 ...
7  | 4  6  7 10 12 14 15 18 20 22 24 26 27 30 32 34 ...
8  | 4  6  8 12 14 16 18 20 22 24 28 30 32 34 36 38 ...
9  | 5  6  9 12 15 18 20 22 25 28 30 32 35 38 40 42 ...
...
		

Crossrefs

Rows 1..2 are A004524(n+2), A302402.
Main diagonal is A302488.

A303335 Array read by antidiagonals: T(m,n) is the number of minimum total dominating sets in the m X n king graph.

Original entry on oeis.org

0, 1, 1, 2, 6, 2, 1, 9, 9, 1, 1, 4, 8, 4, 1, 4, 8, 1, 1, 8, 4, 3, 89, 3, 35, 3, 89, 3, 1, 56, 76, 9, 9, 76, 56, 1, 2, 16, 17, 1, 1, 1, 17, 16, 2, 9, 64, 1, 130, 9, 9, 130, 1, 64, 9, 4, 780, 6, 16, 60, 8684, 60, 16, 6, 780, 4, 1, 304, 229, 1, 89, 493, 493, 89, 1, 229, 304, 1
Offset: 1

Views

Author

Andrew Howroyd, Apr 21 2018

Keywords

Comments

The minimum size of a total dominating set is the total domination number A303378(m, n).

Examples

			Table begins:
=========================================
m\n| 1  2  3   4  5    6   7   8    9
---+-------------------------------------
1  | 0  1  2   1  1    4   3   1    2 ...
2  | 1  6  9   4  8   89  56  16   64 ...
3  | 2  9  8   1  3   76  17   1    6 ...
4  | 1  4  1  35  9    1 130  16    1 ...
5  | 1  8  3   9  1    9  60  89   45 ...
6  | 4 89 76   1  9 8684 493   1   50 ...
7  | 3 56 17 130 60  493 208  40   32 ...
8  | 1 16  1  16 89    1  40 604    1 ...
9  | 2 64  6   1 45   50  32   1 1192 ...
...
		

Crossrefs

Rows 1..2 are A302654, A350817.
Main diagonal is A303156.

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

A303054 Number of minimum total dominating sets in the n-ladder graph.

Original entry on oeis.org

1, 4, 1, 16, 9, 1, 64, 16, 1, 169, 25, 1, 361, 36, 1, 676, 49, 1, 1156, 64, 1, 1849, 81, 1, 2809, 100, 1, 4096, 121, 1, 5776, 144, 1, 7921, 169, 1, 10609, 196, 1, 13924, 225, 1, 17956, 256, 1, 22801, 289, 1, 28561, 324, 1, 35344, 361, 1, 43264, 400, 1, 52441
Offset: 1

Views

Author

Eric W. Weisstein, Apr 17 2018

Keywords

Comments

Each vertex can dominate up to three others. A ladder with a length that is an exact multiple of three can be dominated in only one way with 2n/3 vertices. - Andrew Howroyd, Apr 21 2018

Examples

			From _Andrew Howroyd_, Apr 21 2018: (Start)
a(9) = 1 because there is only one arrangement of 6 vertices that is totally dominating and no set with fewer vertices can be totally dominating:
  .__o__.__.__o__.__.__o__.
     |        |        |
  .__o__.__.__o__.__.__o__.
(End)
		

Crossrefs

Row 2 of A303293.

Programs

  • Mathematica
    Table[Piecewise[{{1, Mod[n, 3] == 0}, {((n^2 + 13 n + 4)/18)^2, Mod[n, 3] == 1}, {((n + 4)/3)^2, Mod[n, 3] == 2}}], {n, 58}] (* Eric W. Weisstein, Apr 23 2018 and Michael De Vlieger, Apr 21 2018 *)
    Table[(916 + 392 n + 213 n^2 + 26 n^3 + n^4 - (-56 + 392 n + 213 n^2 + 26 n^3 + n^4) Cos[2 n Pi/3] + Sqrt[3] (-20 + 7 n + n^2) (28 + 19 n + n^2) Sin[2 n Pi/3])/972, {n, 20}] (* Eric W. Weisstein, Apr 23 2018 *)
    LinearRecurrence[{0, 0, 5, 0, 0, -10, 0, 0, 10, 0, 0, -5, 0, 0, 1}, {1, 4, 1, 16, 9, 1, 64, 16, 1, 169, 25, 1, 361, 36, 1}, 20] (* Eric W. Weisstein, Apr 23 2018 *)
    CoefficientList[Series[(-1 - 4 x - x^2 - 11 x^3 + 11 x^4 + 4 x^5 + 6 x^6 - 11 x^7 - 6 x^8 + x^9 + 5 x^10 + 4 x^11 - x^12 - x^13 - x^14)/(-1 + x^3)^5, {x, 0, 20}], x] (* Eric W. Weisstein, Apr 23 2018 *)
  • PARI
    a(n)={if(n%3==0, 1, if(n%3==1, (n^2 + 13*n + 4)/18, (n + 4)/3))^2} \\ Andrew Howroyd, Apr 21 2018
    
  • PARI
    Vec(x*(1 + 4*x + x^2 + 11*x^3 - 11*x^4 - 4*x^5 - 6*x^6 + 11*x^7 + 6*x^8 - x^9 - 5*x^10 - 4*x^11 + x^12 + x^13 + x^14) / ((1 - x)^5*(1 + x + x^2)^5) + O(x^60)) \\ Colin Barker, Apr 23 2018

Formula

a(n) = 1 for n mod 3 = 0
= ((n^2 + 13*n + 4)/18)^2 for n mod 3 = 1
= ((n + 4)/3)^2 for n mod 3 = 2.
G.f.: x*(-1 - 4*x - x^2 - 11*x^3 + 11*x^4 + 4*x^5 + 6*x^6 - 11*x^7 - 6*x^8 + x^9 + 5*x^10 + 4*x^11 - x^12 - x^13 - x^14)/(-1 + x^3)^5.
a(n) = 5*a(n-3) - 10*a(n-6) + 10*a(n-9) - 5*a(n-12) + a(n-15) for n>15. - Colin Barker, Apr 23 2018

Extensions

Terms a(14) and beyond from Andrew Howroyd, Apr 21 2018

A303142 Number of minimum total dominating sets in the n X n grid graph.

Original entry on oeis.org

0, 4, 2, 16, 160, 144, 4, 256, 1364, 484, 6, 784, 5032, 1444, 8, 2116, 12972, 3364, 10, 4624, 27376, 6724, 12, 8836, 50820, 12100, 14, 15376, 86264, 20164
Offset: 1

Views

Author

Eric W. Weisstein, Apr 19 2018

Keywords

Crossrefs

Main diagonal of A303293.

Extensions

a(6)-a(30) from Andrew Howroyd, Apr 22 2018
Showing 1-7 of 7 results.