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 A358390 #17 Nov 22 2022 11:55:56 %S A358390 1,2,3,25,2117,22581637702 %N A358390 The number of maximal antichains in the Kreweras lattice of non-crossing set partitions of an n-element set. %C A358390 Also similar to the number of maximal antichains in the lattice of set partitions or in the Boolean lattice. %H A358390 Dmitry I. Ignatov, <a href="https://github.com/dimachine/KrewerasNonCrossPartAnti">Supporting iPython code and input files for counting (maximal) antichains of the non-crossing set partition lattice up to n=5</a>, Github repository. %H A358390 G. Kreweras, <a href="https://doi.org/10.1016/0012-365X(72)90041-6">Sur les partitions non croisées d'un cycle</a>, Discrete Math., 4(1972), 333-350. %Y A358390 Cf. A302250 (number of antichains in the lattice of set partitions). %Y A358390 Cf. A326358 (number of maximal antichains in the Boolean lattice). %Y A358390 Cf. A000108 (number of noncrossing partitions of a set of n elements) %K A358390 nonn,hard,more %O A358390 1,2 %A A358390 _Dmitry I. Ignatov_, Nov 13 2022