Let $A = [ai j ] \in M_{n*n}$ is positive semidefinite.
Why does the matrix $[a_{i j} /(i + j )]$ is also positive semidefinite?
Let $A = [ai j ] \in M_{n*n}$ is positive semidefinite.
Why does the matrix $[a_{i j} /(i + j )]$ is also positive semidefinite?