Counting Strings with Given Elementary Symmetric Function
  Evaluations II: Circular Strings 
Frank Ruskey, 
  Department of Computer Science, 
  University of Victoria, Canada. 
C. Robert Miers, 
  Department of Mathematics and Statistics, 
  University of Victoria, Canada. 
Abstract:
Let a be a string over an alphabet that is a finite ring, R. 
The k-th elementary symmetric function evaluated at a is
  denoted Tk(a).
In a companion paper we studied the properties of 
  SR ( n; 
  t1,t2,...,tk ), 
  the set of of length n strings for which 
  Ti ( a ) = ti.
Here we consider the set,
  LR ( n; 
  t1,t2,...,tk ), 
  of equivalence classes under rotation
  of aperiodic strings in 
  SR ( n; 
  t1,t2,...,tk ), 
  sometimes called Lyndon words.
General formulae are established, and then refined for the cases
  where R is the ring of integers Zq 
  or the finite field  Zq.
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