Hello,

By Kolmogorov's 0-1 law, this probability is always 0 or 1. (Or so I guess ^^)

So you just have to see if the corresponding element of is 0 or different from 0 for any n.

(to do so, diagonalise the matrix and you'll have an easy computation for : , where D is the diagonal matrix of eigenvalues, etc, etc...)