login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A116539 Number of zero-one matrices with n ones and no zero rows or columns and with distinct rows, up to permutation of rows. 22
1, 2, 7, 28, 134, 729, 4408, 29256, 210710, 1633107, 13528646, 119117240, 1109528752, 10889570768, 112226155225, 1210829041710, 13640416024410, 160069458445202, 1952602490538038, 24712910192430620, 323964329622503527 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Also the number of labeled hypergraphs spanning an initial interval of positive integers with edge-sizes summing to n. - Gus Wiseman, Dec 18 2018

LINKS

Table of n, a(n) for n=1..21.

P. J. Cameron, T. Prellberg and D. Stark, Asymptotics for incidence matrix classes , arXiv:math/0510155 [math.CO], 2005-2006.

M. Klazar, Extremal problems for ordered hypergraphs, arXiv:math/0305048 [math.CO], 2003.

EXAMPLE

From Gus Wiseman, Dec 18 2018: (Start)

The a(3) = 7 edge-sets:

    {{1,2,3}}

   {{1},{1,2}}

   {{2},{1,2}}

   {{1},{2,3}}

   {{2},{1,3}}

   {{3},{1,2}}

  {{1},{2},{3}}

Inequivalent representatives of the a(4) = 28 0-1 matrices:

  [1111]

.

  [100][1000][010][0100][001][0010][0001][110][110][1100][101][1010][1001]

  [111][0111][111][1011][111][1101][1110][101][011][0011][011][0101][0110]

.

  [10][100][100][1000][100][100][1000][1000][010][010][0100][0100][0010]

  [01][010][010][0100][001][001][0010][0001][001][001][0010][0001][0001]

  [11][101][011][0011][110][011][0101][0110][110][101][1001][1010][1100]

.

  [1000]

  [0100]

  [0010]

  [0001]

(End)

CROSSREFS

Binary matrices with distinct rows and columns, various versions: A059202, A088309, A088310, A088616, A089673, A089674, A093466, A094000, A094223, A116532, A116539, A181230, A259763

Cf. A049311, A058891, A101370, A283877, A306021, A319190.

Sequence in context: A052319 A127783 A297195 * A266467 A141318 A276080

Adjacent sequences:  A116536 A116537 A116538 * A116540 A116541 A116542

KEYWORD

nonn

AUTHOR

Vladeta Jovovic, Mar 27 2006

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 20 21:36 EST 2019. Contains 319336 sequences. (Running on oeis4.)