If $L$ is a lower triangular matrix of ones, does the following matrix have a special name?
$A = \left(\begin{matrix}L & -L \\ -L & L \end{matrix}\right)$
If $L$ is a lower triangular matrix of ones, does the following matrix have a special name?
$A = \left(\begin{matrix}L & -L \\ -L & L \end{matrix}\right)$
It's a special type of "block matrix". Or, as user13838 points out, it can be described as a Kronecker product (or direct product).
(Or, you could just call it $A$.)