A058733 Number of nonisomorphic simple matroids of rank 4 on n labeled points.

1, 3, 11, 49, 617, 185981

Offset

4,2

Links

Table of n, a(n) for n=4..9.

Henry H. Crapo and Gian-Carlo Rota, On the foundations of combinatorial theory. II. Combinatorial geometries, Studies in Appl. Math. 49 (1970), 109-133. [Annotated scanned copy of pages 126 and 127 only]

Henry H. Crapo and Gian-Carlo Rota, On the foundations of combinatorial theory. II. Combinatorial geometries, Studies in Appl. Math. 49 (1970), 109-133.

W. M. B. Dukes, Tables of matroids.

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

W. M. B. Dukes, The number of matroids on a finite set, arXiv:math/0411557 [math.CO], 2004.

W. M. B. Dukes, On the number of matroids on a finite set, Séminaire Lotharingien de Combinatoire 51 (2004), Article B51g.

Dillon Mayhew and Gordon F. Royle, Matroids with nine elements, arXiv:math/0702316 [math.CO], 2007. [See Table 2, p. 9.]

Dillon Mayhew and Gordon F. Royle, Matroids with nine elements, J. Combin. Theory Ser. B 98(2) (2008), 415-431. [See Table 2, p. 420.]

Gordon Royle and Dillon Mayhew, 9-element matroids.

Index entries for sequences related to matroids

Crossrefs

Column k=4 of A058730.

Sequence in context: A331617 A193319 A265905 * A203163 A024333 A024334

Adjacent sequences: A058730 A058731 A058732 * A058734 A058735 A058736

Keyword

nonn,nice,more

Author

N. J. A. Sloane, Dec 31 2000

Extensions

a(9) from Petros Hadjicostas, Oct 09 2019 using the papers by Mayhew and Royle

Status

approved