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 A358041 #22 Aug 20 2023 10:50:04
%S A358041 1,2,3,32,14094
%N A358041 The number of maximal antichains in the lattice of set partitions of an n-element set.
%C A358041 Also similar to the number of maximal antichains in the Boolean lattice.
%H A358041 R. L. Graham, <a href="https://doi.org/10.1007/BF03023067">Maximum antichains in the partition lattice</a>, The Mathematical Intelligencer, 1 (1978), 84-86.
%H A358041 Dmitry I. Ignatov, <a href="https://doi.org/10.1007/978-3-031-40960-8_6">A Note on the Number of (Maximal) Antichains in the Lattice of Set Partitions</a>. In: Ojeda-Aciego, M., Sauerwald, K., Jäschke, R. (eds) Graph-Based Representation and Reasoning. ICCS 2023. Lecture Notes in Computer Science(). Springer, Cham.
%H A358041 Dmitry I. Ignatov, <a href="https://github.com/dimachine/SetPartAnti/">Supporting iPython code and input files for counting (maximal) antichains of the set partition lattice up to n=5</a>, Github repository.
%e A358041 For n = 3 the a(3) = 3 maximal antichains are: {1|2|3}, {1|23, 12|3, 13|2}, and {123}. We use the typical shorthand notation for set partitions where 1|23 denotes {{1}, {2,3}}.
%Y A358041 Cf. A302250 (number of antichains in the lattice of set partitions).
%Y A358041 Cf. A326358 (number of maximal antichains in the Boolean lattice).
%K A358041 nonn,hard,more
%O A358041 1,2
%A A358041 _Dmitry I. Ignatov_, Oct 29 2022