A322451 Number of unlabeled 3-uniform hypergraphs spanning n vertices.

1, 0, 0, 1, 3, 29, 2102, 7011184, 1788775603336, 53304526022885280592, 366299663378889804782337225824, 1171638318502622784366970315264281830913536, 3517726593606524901243694560022510194223171115509135178240

Offset

0,5

Comments

3-uniform means that every edge consists of 3 vertices. - Brendan McKay, Sep 03 2023

Links

Andrew Howroyd, Table of n, a(n) for n = 0..25

Example

Non-isomorphic representatives of the a(5) = 29 hypergraphs:
  {{125}{345}}
  {{123}{245}{345}}
  {{135}{245}{345}}
  {{145}{245}{345}}
  {{123}{145}{245}{345}}
  {{124}{135}{245}{345}}
  {{125}{135}{245}{345}}
  {{134}{235}{245}{345}}
  {{145}{235}{245}{345}}
  {{123}{124}{135}{245}{345}}
  {{123}{145}{235}{245}{345}}
  {{124}{134}{235}{245}{345}}
  {{134}{145}{235}{245}{345}}
  {{135}{145}{235}{245}{345}}
  {{145}{234}{235}{245}{345}}
  {{123}{124}{134}{235}{245}{345}}
  {{123}{134}{145}{235}{245}{345}}
  {{123}{145}{234}{235}{245}{345}}
  {{124}{135}{145}{235}{245}{345}}
  {{125}{135}{145}{235}{245}{345}}
  {{135}{145}{234}{235}{245}{345}}
  {{123}{124}{135}{145}{235}{245}{345}}
  {{124}{135}{145}{234}{235}{245}{345}}
  {{125}{135}{145}{234}{235}{245}{345}}
  {{134}{135}{145}{234}{235}{245}{345}}
  {{123}{124}{135}{145}{234}{235}{245}{345}}
  {{125}{134}{135}{145}{234}{235}{245}{345}}
  {{124}{125}{134}{135}{145}{234}{235}{245}{345}}
  {{123}{124}{125}{134}{135}{145}{234}{235}{245}{345}}

Crossrefs

First differences of A000665.

Cf. A006126, A006129, A038041, A299471, A301922, A302374, A302394, A306017, A306021.

Sequence in context: A255597 A319637 A003190 * A213792 A133663 A270480

Adjacent sequences: A322448 A322449 A322450 * A322452 A322453 A322454

Keyword

nonn

Author

Gus Wiseman, Dec 09 2018

Extensions

a(12) from Andrew Howroyd, Dec 15 2018

Name corrected by Brendan McKay, Sep 03 2023

Status

approved