A292884 Number of ways to shuffle together a multiset of compositions to form a composition of n.
1, 3, 8, 25, 76, 248, 806, 2714, 9205, 31846, 111185, 393224
Offset: 1
Examples
The a(3)=8 shuffles are: (111)<=((111)), (111)<=((1)(11)), (111)<=((1)(1)(1)), (12)<=((12)), (12)<=((1)(2)), (21)<=((21)), (21)<=((1)(2)), (3)<=((3)).
Programs
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Mathematica
nn=10; comps[0]:={{}};comps[n_]:=Join@@Table[Prepend[#,i]&/@comps[n-i],{i,n}]; sps[{}]:={{}};sps[set:{i_,_}]:=Join@@Function[s,Prepend[#,s]&/@sps[Complement[set,s]]]/@Cases[Subsets[set],{i,_}]; dealings[q_]:=Union[Function[ptn,Sort[q[[#]]&/@ptn]]/@sps[Range[Length[q]]]]; Table[Total[Length/@dealings/@comps[n]],{n,nn}]
Extensions
a(12) from Robert Price, Sep 16 2018