A301920 Number of unlabeled uniform connected hypergraphs spanning n vertices.

1, 1, 1, 3, 10, 55, 2369, 14026242, 29284932065996223, 468863491068204425232922367146585, 1994324729204021501147398087008429476673379600542622915802043455294332

Offset

0,4

Comments

A hypergraph is uniform if all edges have the same size.

Links

Andrew Howroyd, Table of n, a(n) for n = 0..13

Example

Non-isomorphic representatives of the a(4) = 10 hypergraphs:
  {{1,2,3,4}}
  {{1,3,4},{2,3,4}}
  {{1,3},{2,4},{3,4}}
  {{1,4},{2,4},{3,4}}
  {{1,2,4},{1,3,4},{2,3,4}}
  {{1,2},{1,3},{2,4},{3,4}}
  {{1,4},{2,3},{2,4},{3,4}}
  {{1,3},{1,4},{2,3},{2,4},{3,4}}
  {{1,2,3},{1,2,4},{1,3,4},{2,3,4}}
  {{1,2},{1,3},{1,4},{2,3},{2,4},{3,4}}

Crossrefs

Row sums of A301924.

Cf. A003465, A006129, A038041, A055621, A298422, A299353, A299354, A301481, A306017-A306021.

Sequence in context: A284645 A081721 A013009 * A203416 A002218 A107871

Adjacent sequences: A301917 A301918 A301919 * A301921 A301922 A301923

Keyword

nonn

Author

Gus Wiseman, Jun 19 2018

Extensions

Terms a(6) and beyond from Andrew Howroyd, Aug 26 2019

Status

approved