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!)
A320800 Number of non-isomorphic multiset partitions of weight n in which both the multiset union of the parts and the multiset union of the dual parts are aperiodic. 9

%I #5 Nov 05 2018 21:01:23

%S 1,1,1,5,14,78,157,881,2267,9257,28397

%N Number of non-isomorphic multiset partitions of weight n in which both the multiset union of the parts and the multiset union of the dual parts are aperiodic.

%C The latter condition is equivalent to the parts having relatively prime sizes.

%C A multiset is aperiodic if its multiplicities are relatively prime.

%C The dual of a multiset partition has, for each vertex, one part consisting of the indices (or positions) of the parts containing that vertex, counted with multiplicity. For example, the dual of {{1,2},{2,2}} is {{1},{1,2,2}}.

%C The weight of a multiset partition is the sum of sizes of its parts. Weight is generally not the same as number of vertices.

%e Non-isomorphic representatives of the a(1) = 1 through a(4) = 14 multiset partitions:

%e {{1}} {{1},{2}} {{1},{2,2}} {{1},{2,2,2}}

%e {{1},{2,3}} {{1},{2,3,3}}

%e {{2},{1,2}} {{1},{2,3,4}}

%e {{1},{2},{2}} {{2},{1,2,2}}

%e {{1},{2},{3}} {{3},{1,2,3}}

%e {{1},{1},{2,3}}

%e {{1},{2},{2,2}}

%e {{1},{2},{3,3}}

%e {{1},{2},{3,4}}

%e {{1},{3},{2,3}}

%e {{2},{2},{1,2}}

%e {{1},{2},{2},{2}}

%e {{1},{2},{3},{3}}

%e {{1},{2},{3},{4}}

%Y Cf. A000740, A000837, A007716, A007916, A100953, A301700, A303386, A303431, A303546, A303547, A316983, A320801-A320810.

%K nonn,more

%O 0,4

%A _Gus Wiseman_, Nov 02 2018

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 April 19 10:56 EDT 2024. Contains 371791 sequences. (Running on oeis4.)