×

Enumeration schemes for words avoiding patterns with repeated letters. (English) Zbl 1210.05005

Summary: We discuss the enumeration of words avoiding patterns with repeated letters. More specifically, we find enumeration schemes (i.e., recurrences) to count pattern-avoiding words using a divide-and-conquer technique, breaking up a set of words based on the pattern formed by the smallest letters of each word. We apply this method to the counting of words avoiding patterns of length 3 and words avoiding any monotone pattern.

MSC:

05A05 Permutations, words, matrices

Software:

InsEnc
PDFBibTeX XMLCite
Full Text: EuDML EMIS