Abstract :
We say the pair of patterns image is multiset Wilf equivalent if, for any multiset M, the number of permutations of M that avoid image is equal to the number of permutations of M that avoid image. In this paper, we find a large new class of multiset Wilf equivalent pairs, namely, the pair (image, image), for image and image a permutation of image. It is the most general multiset Wilf equivalence result to date.
