Hi, it seems your formula is not right because when I checked y_0,y_1,y_2, I find the following:
$$\begin{align}
& {{y}_{1}}=\frac{X{{e}_{i}}+{{e}_{i}}}{\left\| X{{e}_{i}}+{{e}_{i}} \right\|} \\
& {{y}_{2}}=\frac{X{{y}_{1}}+{{e}_{i}}}{\left\| X{{y}_{1}}+{{e}_{i}} \right\|} \\
&...
Let e_i be a unit vector with one 1 in the i-th element. Is the following expression has a recursive presentation?
$$y_N = \sum_{k=0}^N {\frac{{{X^k} e_i}}{\|{{{X^k} e_i}\|}_2}} $$
where X is a n \times n square matrix, and {\| \cdot \|}_2 is a vector norm defined as {\|z\|}_2 =...