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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A317656 Number of free pure symmetric multifunctions whose leaves are the integer partition with Heinz number n.

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%I A317656 #6 Aug 03 2018 08:17:12
%S A317656 0,1,1,1,1,2,1,3,1,2,1,8,1,2,2,10,1,8,1,8,2,2,1,35,1,2,3,8,1,15,1,37,
%T A317656 2,2,2,50,1,2,2,35,1,15,1,8,8,2,1,160,1,8,2,8,1,35,2,35,2,2,1,96,1,2,
%U A317656 8,144,2,15,1,8,2,15,1,299,1,2,8,8,2,15,1,160
%N A317656 Number of free pure symmetric multifunctions whose leaves are the integer partition with Heinz number n.
%C A317656 A free pure symmetric multifunction f in EPSM is either (case 1) a positive integer, or (case 2) an expression of the form h[g_1, ..., g_k] where k > 0, h is in EPSM, each of the g_i for i = 1, ..., k is in EPSM, and for i < j we have g_i <= g_j under a canonical total ordering of EPSM, such as the Mathematica ordering of expressions.
%e A317656 The a(12) = 8 free pure symmetric multifunctions are 1[1[2]], 1[2[1]], 1[1,2], 2[1[1]], 2[1,1], 1[1][2], 1[2][1], 2[1][1].
%t A317656 sps[{}]:={{}};sps[set:{i_,___}]:=Join@@Function[s,Prepend[#,s]&/@sps[Complement[set,s]]]/@Cases[Subsets[set],{i,___}];
%t A317656 mps[set_]:=Union[Sort[Sort/@(#/.x_Integer:>set[[x]])]&/@sps[Range[Length[set]]]];
%t A317656 exprUsing[m_]:=exprUsing[m]=If[Length[m]==0,{},If[Length[m]==1,{First[m]},Join@@Cases[Union[Table[PR[m[[s]],m[[Complement[Range[Length[m]],s]]]],{s,Take[Subsets[Range[Length[m]]],{2,-2}]}]],PR[h_,g_]:>Join@@Table[Apply@@@Tuples[{exprUsing[h],Union[Sort/@Tuples[exprUsing/@p]]}],{p,mps[g]}]]]];
%t A317656 primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
%t A317656 Table[Length[exprUsing[primeMS[n]]],{n,100}]
%Y A317656 Cf. A001003, A052893, A053492, A255906, A277996, A279944, A280000.
%Y A317656 Cf. A317652, A317653, A317654, A317655, A317658.
%K A317656 nonn
%O A317656 1,6
%A A317656 _Gus Wiseman_, Aug 03 2018