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 A358460 #7 Nov 19 2022 08:57:07 %S A358460 1,1,2,5,13,36,103,301,902,2767,8637,27324,87409,282319,919352 %N A358460 Number of locally disjoint ordered rooted trees with n nodes. %C A358460 Locally disjoint means no branch of any vertex overlaps a different (unequal) branch of the same vertex. %e A358460 The a(1) = 1 through a(5) = 13 trees: %e A358460 o (o) (oo) (ooo) (oooo) %e A358460 ((o)) ((o)o) ((o)oo) %e A358460 ((oo)) ((oo)o) %e A358460 (o(o)) ((ooo)) %e A358460 (((o))) (o(o)o) %e A358460 (o(oo)) %e A358460 (oo(o)) %e A358460 (((o))o) %e A358460 (((o)o)) %e A358460 (((oo))) %e A358460 ((o(o))) %e A358460 (o((o))) %e A358460 ((((o)))) %t A358460 aot[n_]:=If[n==1,{{}},Join @@ Table[Tuples[aot/@c],{c,Join@@Permutations/@IntegerPartitions[n-1]}]]; %t A358460 Table[Length[Select[aot[n],FreeQ[#,{___,{___,x_,___},___,{___,x_,___},___}]&]],{n,10}] %Y A358460 The locally non-intersecting version is A143363, unordered A007562. %Y A358460 The unordered version is A316473, ranked by A316495. %Y A358460 A000108 counts ordered rooted trees, unordered A000081. %Y A358460 A358453 counts transitive ordered trees, unordered A290689. %Y A358460 Cf. A006013, A302696, A316471, A316694, A318185, A319378, A324768, A324844. %K A358460 nonn,more %O A358460 1,3 %A A358460 _Gus Wiseman_, Nov 19 2022