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 A318993 #5 Sep 07 2018 04:45:20
%S A318993 1,2,4,3,8,7,16,5,9,19,32,17,64,53,11,128,23,256,67,49,131,512,59,27,
%T A318993 311,25,241,1024,2048,31,719,83,4096,1619,361,331,8192,227,16384,739,
%U A318993 3671,32768,277,81,103,2063,65536,97,1523,2809,8161,131072,262144,17863
%N A318993 Matula-Goebel number of the planted achiral tree determined by the n-th number whose consecutive prime indices are divisible.
%H A318993 Gus Wiseman, <a href="/A318993/a318993.png">The first 81 planted achiral trees corresponding to the first 81 dividing partitions.</a>
%e A318993 The sequence of all planted achiral trees begins: o, (o), (oo), ((o)), (ooo), ((oo)), (oooo), (((o))), ((o)(o)), ((ooo)), (ooooo), (((oo))), (oooooo), ((oooo)), ((((o)))), (ooooooo), (((o)(o))), (oooooooo), (((ooo))), ((oo)(oo)).
%t A318993 primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
%t A318993 ptnToAch[y_]:=Fold[Table[#1,{#2}]&,{},Divide@@@Partition[Append[y,1],2,1]];
%t A318993 MGNumber[_[]]:=1;MGNumber[x:_[__]]:=If[Length[x]==1,Prime[MGNumber[x[[1]]]],Times@@Prime/@MGNumber/@x];
%t A318993 MGNumber/@ptnToAch/@Reverse/@primeMS/@Select[Range[100],Or[#==1,PrimeQ[#],Divisible@@Reverse[primeMS[#]]]&]
%Y A318993 Cf. A000040, A001221, A003238, A008480, A061775, A214577, A318990, A318991, A318992.
%K A318993 nonn
%O A318993 1,2
%A A318993 _Gus Wiseman_, Sep 06 2018