recurrence relation

from The Free On-line Dictionary of Computing (8 July 2008)

recurrence relation

   <mathematics> An {equation} that defines each element of a
   {sequence} in terms of one or more earlier elements.  E.g. The
   {Fibonacci sequence},

    X[1] = 1
    X[2] = 1
    X[n] = X[n-1] + X[n-2]

   Some recurrence relations can be converted to "closed form"
   where X[n] is defined purely in terms of n, without reference
   to earlier elements.

   (2008-01-14)