Finite Semilattices with Many Congruences
Gábor Czédli · SZTE Publicatio Repozitórium (University of Szeged) · 2018
For an integer n ≥ 2, let NCSL(n) denote the set of sizes of congruence lattices of n-element semilattices.We find the four largest numbers belonging to NCSL(n), provided that n is large enough to ensure that |NCSL(n)| ≥ 4. Furthermore, we describe the n-element semilattices witnessing these numbers.1991