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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A058720 Triangle T(n,k) giving number of simple matroids of rank k on n labeled points (n >= 2, 2<=k<=n). 3

%I

%S 1,1,1,1,5,1,1,31,16,1,1,352,337,42,1,1,8389,18700,2570,99,1,1,433038,

%T 7642631,907647,16865,219,1

%N Triangle T(n,k) giving number of simple matroids of rank k on n labeled points (n >= 2, 2<=k<=n).

%H W. M. B. Dukes, <a href="http://www.stp.dias.ie/~dukes/matroid.html">Tables of matroids</a>

%H W. M. B. Dukes, <a href="http://www.stp.dias.ie/~dukes/phd.html">Counting and Probability in Matroid Theory</a>, Ph.D. Thesis, Trinity College, Dublin, 2000.

%H <a href="/index/Mat#matroid">Index entries for sequences related to matroids</a>

%H W. M. B. Dukes, <a href="http://arXiv.org/abs/math.CO/0411557">On the number of matroids on a finite set</a>

%e 1; 1,1; 1,5,1; 1,31,16,1; ...

%Y Cf. A058716, A058730. Row sums give A058721. Diagonals give (A056642)+1, A058722.

%K nonn,tabl,nice

%O 2,5

%A _N. J. A. Sloane_, Dec 31 2000

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified May 22 05:06 EDT 2013. Contains 225511 sequences.