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 1-5 of 5 results.

A303144 Number of minimum total dominating sets in the n X n white bishop graph.

Original entry on oeis.org

1, 4, 1, 4, 61, 12, 104, 2540, 270, 5760, 184710, 13140, 458640, 20036160, 982800, 53726400, 3042295200, 110224800, 8497742400, 611011447200, 16922228400, 1763683891200, 157184659447200, 3435788664000, 463679536320000, 50243200517664000, 888196949640000, 150876035934624000, 19562163412303512000
Offset: 2

Views

Author

Eric W. Weisstein, Apr 19 2018

Keywords

Comments

For n >= 3, the total domination number is given by floor(2*n/3) = A004523(n). - Andrew Howroyd, May 17 2025

Crossrefs

Cf. A303141 (black bishop).

Programs

Extensions

a(8)-a(10) from Andrew Howroyd, Apr 20 2018
a(11) from Eric W. Weisstein, Apr 02 2025
a(12) onwards from Andrew Howroyd, May 16 2025

A321673 Number of minimum total dominating sets in the n X n bishop graph.

Original entry on oeis.org

0, 1, 16, 1, 8, 3721, 108, 10816, 6568440, 72900, 31449600, 34117784100, 165564000, 210350649600, 402994899820800, 965895840000, 2867571383040000, 9255560083943040000, 12074509581120000, 72211625896757760000, 373919369489319044160000, 286361814021766560000, 3107808843778161008640000
Offset: 1

Views

Author

Eric W. Weisstein, Nov 16 2018

Keywords

Crossrefs

Cf. A303141 (black bishop graph).
Cf. A303144 (white bishop graph).

Programs

Formula

a(n) = A303141(n) * A303144(n). - Andrew Howroyd, Nov 16 2018

Extensions

a(8)-a(10) from Andrew Howroyd, Nov 16 2018
a(11) from Eric W. Weisstein, Apr 03 2025
a(12) onwards from Andrew Howroyd, May 16 2025

A303145 Number of total dominating sets in the n X n black bishop graph.

Original entry on oeis.org

0, 1, 16, 143, 5468, 199095, 28216660, 3855890801, 2063573357664, 1084629728348393, 2257651988909632680, 4666227312488067563575, 38431519470524295069404276, 315759892137678954308707379391, 10364113216536074591340863505339180, 339917045534987610111076281503519527705
Offset: 1

Views

Author

Eric W. Weisstein, Apr 19 2018

Keywords

Crossrefs

Cf. A303147 (white bishop).

Programs

Extensions

a(8)-a(10) from Andrew Howroyd, Apr 20 2018
a(11) onwards from Andrew Howroyd, May 16 2025

A323500 Number of minimum dominating sets in the n X n black bishop graph.

Original entry on oeis.org

1, 2, 1, 5, 52, 22, 6, 108, 2964, 672, 120, 4680, 245520, 38160, 5040, 342720, 29292480, 3467520, 362880, 38102400, 4819046400, 460857600, 39916800, 5987520000, 1050690009600, 84304281600, 6227020800, 1264085222400, 293878019635200, 20312541849600
Offset: 1

Views

Author

Eric W. Weisstein, Jan 16 2019

Keywords

Crossrefs

Cf. A182333 (bishop graph), A323501 (white bishop graph).

Programs

  • Mathematica
    Table[Piecewise[{{1, n == 1}, {(n/2)! (n + 1)/2, Mod[n, 4] == 0}, {((n - 1)/2)! (n^3 + 3 n^2 + 2 n - 2)/8, Mod[n, 4] == 1}, {(n/2 - 1)! (n^2 + n + 2)/4, Mod[n, 4] == 2}, {((n - 1)/2)!, Mod[n, 4] == 3}}], {n, 20}] (* Eric W. Weisstein, Feb 27 2025 *)
  • PARI
    \\ See A286886 for DomSetCount, Bishop.
    a(n)={Vec(DomSetCount(Bishop(n, 0), x + O(x^((n+3)\2))))[1]} \\ Andrew Howroyd, Sep 08 2019
    
  • PARI
    a(n)=if(n==1, 1, (n\4*2)!*if(n%4<2, if(n%2==0, (n+1)/2, (n^3 + 3*n^2 + 2*n - 2)/8), if(n%2==0, (n^2+n+2)/4, (n-1)/2))); \\ Andrew Howroyd, Sep 09 2019

Formula

From Andrew Howroyd, Sep 09 2019: (Start)
a(n) = (n/2)! * (n + 1)/2 for n mod 4 = 0;
a(n) = ((n-1)/2)! * (n^3 + 3*n^2 + 2*n - 2)/8 for n mod 4 = 1, n > 1;
a(n) = (n/2-1)! * (n^2 + n + 2)/4 for n mod 4 = 2;
a(n) = ((n-1)/2)! for n mod 4 = 3.
(End)

Extensions

Terms a(11) and beyond from Andrew Howroyd, Sep 08 2019

A381726 Number of minimum connected dominating sets in the n X n black bishop graph.

Original entry on oeis.org

1, 2, 1, 1, 2, 13, 83, 513, 4052, 41197, 462069, 5597201, 76094134, 1153902701, 18981358311, 336018968449, 6413439874792, 131386321421901, 2867812411156521, 66426533670738769, 1629082910078009770, 42175861619149917325, 1148999152027728530363, 32856688248674995989889
Offset: 1

Views

Author

Eric W. Weisstein, Mar 05 2025

Keywords

Crossrefs

Cf. A381727 (white bishop).

Programs

  • Mathematica
    Join[{1, 2}, Table[Sum[(2 k - 1)^(n - 2 k - 1) (n - 2 k)^(2 (k - 1)), {k, Floor[(n - 1)/2]}], {n, 3, 20}]] (* Eric W. Weisstein, Mar 22 2025 *)
  • PARI
    \\ B(n,k) is A072590.
    B(n,k) = n^(k-1) * k^(n-1)
    a(n) = if(n <= 2, n, sum(k=1, (n-1)\2, B(n-2*k, 2*k-1))) \\ Andrew Howroyd, Mar 20 2025

Formula

a(n) = Sum_{k=1..floor((n-1)/2)} A072590(n-2*k, 2*k-1) for n >= 3. - Andrew Howroyd, Mar 20 2025

Extensions

a(10) onwards from Andrew Howroyd, Mar 20 2025
Showing 1-5 of 5 results.