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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A304983 Number of unlabeled clutters (connected antichains) spanning n vertices with singleton edges allowed. 8
 1, 1, 3, 14, 118, 2916, 819473 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Table of n, a(n) for n=0..6. FORMULA Inverse Euler transform of A304997. - Andrew Howroyd, Aug 14 2019 EXAMPLE Non-isomorphic representatives of the a(3) = 14 clutters: {{1,2,3}} {{1,3},{2,3}} {{3},{1,2,3}} {{1,2},{1,3},{2,3}} {{3},{1,2},{2,3}} {{3},{1,3},{2,3}} {{2},{3},{1,2,3}} {{1},{2},{3},{1,2,3}} {{2},{3},{1,2},{1,3}} {{3},{1,2},{1,3},{2,3}} {{2},{3},{1,3},{2,3}} {{1},{2},{3},{1,3},{2,3}} {{2},{3},{1,2},{1,3},{2,3}} {{1},{2},{3},{1,2},{1,3},{2,3}} CROSSREFS Cf. A048143, A198085, A261006, A304912, A304981, A304982, A304983, A304984, A304985, A304986, A304997. Sequence in context: A122081 A007140 A161936 * A349013 A260887 A127850 Adjacent sequences: A304980 A304981 A304982 * A304984 A304985 A304986 KEYWORD nonn,more AUTHOR Gus Wiseman, May 23 2018 EXTENSIONS a(5)-a(6) from Andrew Howroyd, Aug 14 2019 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.

Last modified February 28 16:26 EST 2024. Contains 370400 sequences. (Running on oeis4.)