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 A330626 #6 Dec 27 2019 08:58:01
%S A330626 1,1,1,3,17,100,755
%N A330626 Number of non-isomorphic series/singleton-reduced rooted trees whose leaves are sets (not necessarily disjoint) with a total of n atoms.
%C A330626 A series/singleton-reduced rooted tree on a multiset m is either the multiset m itself or a sequence of series/singleton-reduced rooted trees, one on each part of a multiset partition of m that is neither minimal (all singletons) nor maximal (only one part).
%e A330626 Non-isomorphic representatives of the a(1) = 1 through a(4) = 17 trees:
%e A330626 {1} {1,2} {1,2,3} {1,2,3,4}
%e A330626 {{1},{1,2}} {{1},{1,2,3}}
%e A330626 {{1},{2,3}} {{1,2},{1,2}}
%e A330626 {{1,2},{1,3}}
%e A330626 {{1},{2,3,4}}
%e A330626 {{1,2},{3,4}}
%e A330626 {{1},{1},{1,2}}
%e A330626 {{1},{1},{2,3}}
%e A330626 {{1},{2},{1,2}}
%e A330626 {{1},{2},{1,3}}
%e A330626 {{1},{2},{3,4}}
%e A330626 {{1},{{1},{1,2}}}
%e A330626 {{1},{{1},{2,3}}}
%e A330626 {{1},{{2},{1,2}}}
%e A330626 {{1},{{2},{1,3}}}
%e A330626 {{1},{{2},{3,4}}}
%e A330626 {{2},{{1},{1,3}}}
%Y A330626 The non-singleton-reduced version is A330624.
%Y A330626 The generalization where leaves are multisets is A330470.
%Y A330626 A labeled version is A330628 (strongly normal).
%Y A330626 The case with all atoms distinct is A004114.
%Y A330626 The balanced version is A330668.
%Y A330626 Cf. A000669, A004111, A005804, A007716, A141268, A330465, A330625, A330627, A330654, A330663, A330677.
%K A330626 nonn,more
%O A330626 0,4
%A A330626 _Gus Wiseman_, Dec 26 2019