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.
%I A316695 #6 Jul 10 2018 21:15:39 %S A316695 0,1,1,1,1,1,1,2,1,1,1,3,1,1,1,5,1,3,1,3,1,1,1,8,1,1,2,3,1,4,1,10,1,1, %T A316695 1,12,1,1,1,8,1,4,1,3,3,1,1,23,1,3,1,3,1,8,1,8,1,1,1,16,1,1,3,24,1,4, %U A316695 1,3,1,4,1,37,1,1,3,3,1,4,1,23,5,1,1,16 %N A316695 Number of series-reduced locally disjoint rooted trees whose leaves form the integer partition with Heinz number n. %C A316695 A rooted tree is series-reduced if every non-leaf node has at least two branches. It is locally disjoint if no branch overlaps any other (unequal) branch of the same root. %C A316695 The Heinz number of an integer partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k). %e A316695 The a(24) = 8 trees: %e A316695 (1(1(12))) %e A316695 (1(2(11))) %e A316695 (2(1(11))) %e A316695 (1(112)) %e A316695 (2(111)) %e A316695 (11(12)) %e A316695 (12(11)) %e A316695 (1112) %t A316695 sps[{}]:={{}}; %t A316695 sps[set:{i_,___}]:=Join@@Function[s,Prepend[#,s]&/@sps[Complement[set,s]]]/@Cases[Subsets[set],{i,___}]; %t A316695 mps[set_]:=Union[Sort[Sort/@(#/.x_Integer:>set[[x]])]&/@sps[Range[Length[set]]]]; %t A316695 disjointQ[u_]:=Apply[And,Outer[#1==#2||Intersection[#1,#2]=={}&,u,u,1],{0,1}]; %t A316695 gro[m_]:=gro[m]=If[Length[m]==1,List/@m,Union[Sort/@Join@@(Tuples[gro/@#]&/@Select[mps[m],Length[#]>1&])]]; %t A316695 Table[Length[Select[gro[If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]]],And@@Cases[#,q:{__List}:>disjointQ[q],{0,Infinity}]&]],{n,100}] %Y A316695 Cf. A000081, A000669, A001678, A056239, A141268, A292504, A296150, A316471, A316651, A316652, A316655. %K A316695 nonn %O A316695 1,8 %A A316695 _Gus Wiseman_, Jul 10 2018