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A058720 Triangle T(n,k) giving number of simple matroids of rank k on n labeled points (n >= 2, 2<=k<=n). 3
1, 1, 1, 1, 5, 1, 1, 31, 16, 1, 1, 352, 337, 42, 1, 1, 8389, 18700, 2570, 99, 1, 1, 433038, 7642631, 907647, 16865, 219, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

2,5

LINKS

Table of n, a(n) for n=2..29.

W. M. B. Dukes, Tables of matroids

W. M. B. Dukes, Counting and Probability in Matroid Theory, Ph.D. Thesis, Trinity College, Dublin, 2000.

Index entries for sequences related to matroids

W. M. B. Dukes, On the number of matroids on a finite set

EXAMPLE

1; 1,1; 1,5,1; 1,31,16,1; ...

CROSSREFS

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

Sequence in context: A143213 A172377 A156587 * A015116 A322220 A174790

Adjacent sequences:  A058717 A058718 A058719 * A058721 A058722 A058723

KEYWORD

nonn,tabl,nice

AUTHOR

N. J. A. Sloane, Dec 31 2000

STATUS

approved

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Last modified April 26 12:07 EDT 2019. Contains 322472 sequences. (Running on oeis4.)