LaTeX.org

Dear all,

I'm trying to type the following matrix:
matrixf.png

But I could only get this:
mymatrix.png

I used the following code:
\renewcommand{\arraystretch}{2}
\[
g :=\left(
\begin{array}{c|c}
\mathbf{2^D} & \textbf{1} \\ \hline
\textbf{1} & \begin{array}{cc}
\boldsymbol{1^\alpha ...