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.

Previous Showing 11-14 of 14 results.

A195649 Number of ways to place 10n nonattacking kings on a 20 x 2n chessboard.

Original entry on oeis.org

11264, 5266069, 714611200, 50123713793, 2335042206624, 82425144219429, 2383116363555182, 59315924213143597, 1314578079936797520, 26568150968269086211, 498306336520679626558, 8788579757709800395287, 147246060712874767006100, 2362334876238883501403023
Offset: 1

Views

Author

Vaclav Kotesovec, Sep 22 2011

Keywords

Crossrefs

Column k=10 of A350819.

Formula

Recurrence order is 1318.

A195650 Number of ways to place 11n nonattacking kings on a 22 x 2n chessboard.

Original entry on oeis.org

24576, 18174084, 3449705600, 317076250136, 18589546217696, 803491953235264, 27889602664055396, 821112680030028632, 21279238303065874504, 498306336520679626558, 10749154284380665611224, 216711725342137199240416, 4129262403388762742636600
Offset: 1

Views

Author

Vaclav Kotesovec, Sep 22 2011

Keywords

Crossrefs

Column k=11 of A350819.

Formula

Recurrence order is 2321.

A195651 Number of ways to place 12n nonattacking kings on a 24 x 2n chessboard.

Original entry on oeis.org

53248, 61892669, 16333065216, 1955475353217, 143422674213726, 7545414941610145, 312546900470579954, 10819171744710664383, 325878859655043000344, 8788579757709800395287, 216711725342137199240416, 4963704194366362387891227, 106899958975789427315593702
Offset: 1

Views

Author

Vaclav Kotesovec, Sep 22 2011

Keywords

Crossrefs

Column k=12 of A350819.

Formula

Recurrence order is 5672.

A350818 Array read by antidiagonals: T(m,n) is the number of maximum independent sets in the m X n king graph.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 4, 1, 1, 1, 3, 4, 4, 3, 1, 1, 1, 12, 1, 12, 1, 1, 1, 4, 8, 9, 9, 8, 4, 1, 1, 1, 32, 1, 79, 1, 32, 1, 1, 1, 5, 16, 16, 27, 27, 16, 16, 5, 1, 1, 1, 80, 1, 408, 1, 408, 1, 80, 1, 1, 1, 6, 32, 25, 81, 64, 64, 81, 25, 32, 6, 1
Offset: 0

Views

Author

Andrew Howroyd, Jan 17 2022

Keywords

Comments

The maximum size of an independent set is the independence number which in the case of an m X n king graph is given by ceiling(m/2)*ceiling(n/2).

Examples

			Table begins:
=============================================
m\n | 0 1  2  3    4   5     6   7      8
----+----------------------------------------
  0 | 1 1  1  1    1   1     1   1      1 ...
  1 | 1 1  2  1    3   1     4   1      5 ...
  2 | 1 2  4  4   12   8    32  16     80 ...
  3 | 1 1  4  1    9   1    16   1     25 ...
  4 | 1 3 12  9   79  27   408  81   1847 ...
  5 | 1 1  8  1   27   1    64   1    125 ...
  6 | 1 4 32 16  408  64  3600 256  26040 ...
  7 | 1 1 16  1   81   1   256   1    625 ...
  8 | 1 5 80 25 1847 125 26040 625 281571 ...
  ...
		

Crossrefs

Formula

T(m,n) = T(n,m).
T(2*m+1, 2*n+1) = 1.
T(2*m, 2*n+1) = (1+m)^(1+n).
T(2*m, 2*n) = A350819(m, n).
Previous Showing 11-14 of 14 results.