Browsing by Author "Workneh, Daniel"

Now showing 1 - 1 of 1
  • No Thumbnail Available
    Item
    On Pattern Avoiding Permutations
    (Addis Ababa University, 2012-06) Workneh, Daniel; Getu, Seyoum (PhD)
    Finding the Number of n-permutations avoiding a pattern q and also _nding the Stanley-Wilf limit of this pattern are some of the most di_cult questions in the theory of pattern avoidance. Very few a_rmative answers are known regarding these problems. One of the most prominent ones is the Simon-Schimidt bijection from which we can _nd the Stanley-Wilf limit of patterns of length three. The aim of this work is to generalize an upper bound for the Stanley-Wilf limit of an in_nite sequence of patterns using a result of particular kind. We start by introducing major results in pattern avoidance and studying their behaviour deeply. In particular, patterns of length three and four. Generalizations for an upper bound of the Stanley-Wilf limit of the pattern 1324 to an in_nite sequences of patterns are the main results of this work and one of them is an improvement of the previous result of Mikl_os Bona.