login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A322399 Number of non-isomorphic 2-edge-connected clutters spanning n vertices. 1
0, 0, 2, 12, 149 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
COMMENTS
A clutter is a connected antichain of sets. It is 2-edge-connected if it cannot be disconnected by removing any single edge. Compare to blobs or 2-vertex-connected clutters (A304887).
LINKS
EXAMPLE
Non-isomorphic representatives of the a(4) = 12 clutters:
{{1,4},{2,3,4}}
{{1,3,4},{2,3,4}}
{{1,4},{2,4},{3,4}}
{{1,3},{1,4},{2,3,4}}
{{1,2},{1,3,4},{2,3,4}}
{{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}}
{{1,2},{1,3},{1,4},{2,3,4}}
{{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
Sequence in context: A001927 A289987 A105558 * A340026 A279011 A279183
KEYWORD
nonn,more
AUTHOR
Gus Wiseman, Dec 06 2018
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 28 09:04 EDT 2024. Contains 371240 sequences. (Running on oeis4.)