I need to calculate a matrix $A$ (at least some elements of it, see below) as defined by the following equation $$ A=B(\mathbb{1}-B)^{-1} $$ where B is a square matrix of dimension $N$ and $\mathbb{1}$ is $N \times N$ identity matrix. Inspired by this post: https://www.johndcook.com/blog/2010/01/19/dont-invert-that-matrix/ I was wondering if I really need to invert $\mathbb{1}-B$ in my case, of if there's some easier way. Keep in mind that: - $N$ in my case is quite large, its order of magnitude can be ten thousand. - I don't need to know the full matrix $A$, I just need a few elements in the upper left corner, let's say $A_{00}$, $A_{01}$, $A_{11}$, $A_{02}$, $A_{12}$, $A_{22}$ would be perfect.