I have a symmetric matrix with three diagonal elements, two of which are off the main diagonal. I wanted to ask if there was a name for this type of matrix. If it helps, I couldn't find it in Wikipedia's "List of Named Matricies."
$$X=\left[\begin{array}{cccccccc}
a_1 & 0 & 0 & 0 & b_1 & 0 & 0 & 0 \\
0 & a_2 & 0 & 0 & 0 & b_2 & 0 & 0 \\
0 & 0 & a_3 & 0 & 0 & 0 & b_3 & 0 \\
0 & 0 & 0 & a_4 & 0 & 0 & 0 & b_4 \\
b_1 & 0 & 0 & 0 & a_5 & 0 & 0 & 0 \\
0 & b_2 & 0 & 0 & 0 & a_6 & 0 & 0 \\
0 & 0 & b_3 & 0 & 0 & 0 & a_7 & 0 \\
0 & 0 & 0 & b_4 & 0 & 0 & 0 & a_8 \\
\end{array}\right]$$
Is there any "special" name for this type of Matrix?