A356934 Number of multisets of odd-size multisets whose multiset union is a size-n multiset covering an initial interval with weakly decreasing multiplicities.
1, 1, 2, 6, 17, 46, 166, 553, 2093
Offset: 0
Examples
The a(1) = 1 through a(4) = 17 multiset partitions: {{1}} {{1},{1}} {{1,1,1}} {{1},{1,1,1}} {{1},{2}} {{1,1,2}} {{1},{1,1,2}} {{1,2,3}} {{1},{1,2,2}} {{1},{1},{1}} {{1},{1,2,3}} {{1},{1},{2}} {{1},{2,3,4}} {{1},{2},{3}} {{2},{1,1,1}} {{2},{1,1,2}} {{2},{1,1,3}} {{2},{1,3,4}} {{3},{1,1,2}} {{3},{1,2,4}} {{4},{1,2,3}} {{1},{1},{1},{1}} {{1},{1},{1},{2}} {{1},{1},{2},{2}} {{1},{1},{2},{3}} {{1},{2},{3},{4}}
Crossrefs
A011782 counts multisets covering an initial interval.
Programs
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Mathematica
sps[{}]:={{}};sps[set:{i_,_}]:=Join@@Function[s,Prepend[#,s]&/@sps[Complement[set,s]]]/@Cases[Subsets[set],{i,_}]; mps[set_]:=Union[Sort[Sort/@(#/.x_Integer:>set[[x]])]&/@sps[Range[Length[set]]]]; strnorm[n_]:=Flatten[MapIndexed[Table[#2,{#1}]&,#]]&/@IntegerPartitions[n]; Table[Length[Select[Join@@mps/@strnorm[n],OddQ[Times@@Length/@#]&]],{n,0,5}]
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