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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A321679 Number of non-isomorphic weight-n antichains (not necessarily strict) of sets. 9
 1, 1, 3, 5, 12, 19, 45, 75, 170, 314, 713 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS The weight of a multiset partition is the sum of sizes of its parts. Weight is generally not the same as number of vertices. LINKS Table of n, a(n) for n=0..10. EXAMPLE Non-isomorphic representatives of the a(1) = 1 through a(5) = 19 antichains: {{1}} {{1,2}} {{1,2,3}} {{1,2,3,4}} {{1,2,3,4,5}} {{1},{1}} {{1},{2,3}} {{1,2},{1,2}} {{1},{2,3,4,5}} {{1},{2}} {{1},{1},{1}} {{1},{2,3,4}} {{1,2},{3,4,5}} {{1},{2},{2}} {{1,2},{3,4}} {{1,4},{2,3,4}} {{1},{2},{3}} {{1,3},{2,3}} {{1},{1},{2,3,4}} {{1},{1},{2,3}} {{1},{2,3},{2,3}} {{1},{2},{3,4}} {{1},{2},{3,4,5}} {{1},{1},{1},{1}} {{1},{2,3},{4,5}} {{1},{1},{2},{2}} {{1},{2,4},{3,4}} {{1},{2},{2},{2}} {{1},{1},{1},{2,3}} {{1},{2},{3},{3}} {{1},{2},{2},{3,4}} {{1},{2},{3},{4}} {{1},{2},{3},{4,5}} {{1},{1},{1},{1},{1}} {{1},{1},{2},{2},{2}} {{1},{2},{2},{2},{2}} {{1},{2},{2},{3},{3}} {{1},{2},{3},{3},{3}} {{1},{2},{3},{4},{4}} {{1},{2},{3},{4},{5}} CROSSREFS Cf. A006126, A049311, A096827, A285572, A293993, A293994, A318099, A319719, A319721, A320799, A321678. Sequence in context: A341710 A024458 A143643 * A266819 A245939 A089292 Adjacent sequences: A321676 A321677 A321678 * A321680 A321681 A321682 KEYWORD nonn,more AUTHOR Gus Wiseman, Nov 16 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.

Last modified April 19 08:45 EDT 2024. Contains 371782 sequences. (Running on oeis4.)