A358390 The number of maximal antichains in the Kreweras lattice of non-crossing set partitions of an n-element set.

1, 2, 3, 25, 2117, 22581637702

Offset: 1

Author

Dmitry I. Ignatov, Nov 13 2022

Keywords

• nonn
• hard
• more

Comments

Also similar to the number of maximal antichains in the lattice of set partitions or in the Boolean lattice.

Links

• Dmitry I. Ignatov, Supporting iPython code and input files for counting (maximal) antichains of the non-crossing set partition lattice up to n=5, Github repository.
• G. Kreweras, Sur les partitions non croisées d'un cycle, Discrete Math., 4(1972), 333-350.

Crossrefs

Cf. A302250 (number of antichains in the lattice of set partitions).

Cf. A326358 (number of maximal antichains in the Boolean lattice).

Cf. A000108 (number of noncrossing partitions of a set of n elements)