A320813 Number of non-isomorphic multiset partitions of an aperiodic multiset of weight n such that there are no singletons and all parts are themselves aperiodic multisets.
1, 0, 1, 2, 5, 13, 33, 104, 293, 938, 2892
Offset: 0
Examples
Non-isomorphic representatives of the a(2) = 1 through a(5) = 13 multiset partitions: {{1,2}} {{1,2,2}} {{1,2,2,2}} {{1,1,2,2,2}} {{1,2,3}} {{1,2,3,3}} {{1,2,2,2,2}} {{1,2,3,4}} {{1,2,2,3,3}} {{1,2},{3,4}} {{1,2,3,3,3}} {{1,3},{2,3}} {{1,2,3,4,4}} {{1,2,3,4,5}} {{1,2},{1,2,2}} {{1,2},{2,3,3}} {{1,2},{3,4,4}} {{1,2},{3,4,5}} {{1,3},{2,3,3}} {{1,4},{2,3,4}} {{2,3},{1,2,3}}
Crossrefs
Programs
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Mathematica
sps[{}]:={{}};sps[set:{i_,_}]:=Join@@Function[s,Prepend[#,s]& /@ sps[Complement[set,s]]]/@Cases[Subsets[set],{i,_}]; mpm[n_]:=Join@@Table[Union[Sort[Sort /@ (#/.x_Integer:>s[[x]])]&/@sps[Range[n]]],{s,Flatten[MapIndexed[Table[#2,{#1}]&,#]]& /@ IntegerPartitions[n]}]; brute[m_]:=First[Sort[Table[Sort[Sort /@ (m/.Rule@@@Table[{i,p[[i]]},{i,Length[p]}])], {p,Permutations[Union@@m]}]]]; aperQ[m_]:=Length[m]==0||GCD@@Length/@Split[Sort[m]]==1; Table[Length[Union[brute /@ Select[mpm[n],And[Min@@Length/@#>1,aperQ[Join@@#]&&And@@aperQ /@ #]&]]],{n,0,7}] (* Gus Wiseman, Jan 19 2024 *)
Extensions
Definition corrected by Gus Wiseman, Jan 19 2024
Comments