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.

A002564 Number of different ways one can attack all squares on an n X n chessboard using the minimum number of queens.

Original entry on oeis.org

1, 4, 1, 12, 186, 4, 86, 4860, 114, 8, 2, 8, 288, 4632, 205832, 2968, 124, 16, 84
Offset: 1

Views

Author

Keywords

Comments

Number of distinct solutions to minimum dominating set on queens' graph Q(n). See A002563 for non-isomorphic solutions.
For same problem, but with non-attacking queens, see A002568. - Vaclav Kotesovec, Sep 07 2012
In other words, number of minimum dominating sets in the n X n queen graph. - Eric W. Weisstein, Dec 31 2017
For n > 2, also the number of minimal edge covers in the n X n queen graph. - Eric W. Weisstein, Dec 09 2024
a(20) >= 4152. - Eric W. Weisstein, Jul 28 2025

References

  • W. Ahrens, Mathematische Unterhaltungen und Spiele, second edition (1910), Vol. 1, p. 301.
  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

A075458 gives number of queens required. - Sean A. Irvine, Apr 05 2014

Extensions

New name of the sequence from Vaclav Kotesovec, Sep 07 2012
a(9)-a(10) from Vaclav Kotesovec, Sep 07 2012
a(11) from Svyatoslav Starkov, Sep 16 2013
a(12)-a(13) from Sean A. Irvine, Apr 07 2014
Definition edited by N. J. A. Sloane, Dec 25 2017 at the suggestion of Brendan McKay.
a(14) from Andy Huchala, Mar 13 2024
a(15)-a(19) from Mia Muessig, Oct 04 2024

A002567 Number of nonisomorphic solutions to minimal independent dominating set on queens' graph Q(n).

Original entry on oeis.org

1, 1, 1, 2, 2, 17, 1, 91, 16, 1, 1, 105, 4, 55, 1314, 16, 2, 28
Offset: 1

Views

Author

Keywords

References

  • W. Ahrens, Mathematische Unterhaltungen und Spiele, second edition (1910), Vol. 1, p. 301.
  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

See A002568 for the number of distinct solutions.
A075324 gives number of queens required.

Extensions

a(9) corrected by Peter Gibbons, May 30 2004

A286883 Number of minimal dominating sets in the n X n queen graph.

Original entry on oeis.org

1, 4, 21, 194, 2579, 48028, 1023698, 28281838
Offset: 1

Views

Author

Eric W. Weisstein, Aug 02 2017

Keywords

Crossrefs

Extensions

a(5)-a(8) from Andrew Howroyd, Aug 19 2017

A002566 Number of ways to attack all squares on an n X n chessboard using the smallest possible number of queens with each queen attacking at least one other.

Original entry on oeis.org

0, 6, 20, 12, 70, 960, 22, 352, 10, 216, 4814, 72
Offset: 1

Views

Author

Keywords

Comments

Differs from A002564 and A002568 in that each queen is attacking at least one other queen.
M. A. Sainte-Laguë paper has "a(6)=900?".
In other words, the number of minimum total dominating sets in the n X n queen graph. - Eric W. Weisstein, Apr 19 2018

References

  • W. Ahrens, Mathematische Unterhaltungen und Spiele, second edition (1910), Vol. 1, p. 301.
  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Cf. A002565 (number of ways up to isomorphism).

Extensions

a(6) corrected and a(9)-a(11) by Sean A. Irvine, Apr 05 2014
Better name from Sean A. Irvine, Apr 05 2014
a(12) from Eric W. Weisstein, Apr 05 2025
Showing 1-4 of 4 results.