The first three largest numbers of subuniverses of semilattices
Delbrin Ahmed, Eszter K. Horváth · Miskolc mathematical notes/Mathematical notes · 2021
Let (L, ∨) be a finite n-element semilattice where n ≥ 5. We prove that the first largest number of subuniverses of an n-element semilattice is 2 n , while the second largest number is 28 • 2 n-5 and the third one is 26 • 2 n-5 .Also, we describe the n-element semilattices with exactly 2 n , 28 • 2 n-5 or 26 • 2 n-5 subuniverses.