The Möbius function of separable and decomposable permutations

Abstrakt

We give a recursive formula for the Möbius function of an interval [p,q] in the poset of permutations ordered by pattern containment in the case where q is a decomposable permutation, that is, consists of two blocks where the first one contains all the letters 1,2,...,k for some k.

Klíčová slova

• Möbius function
• separable permutations