How to define template inside a template class?

I can find template definition for matrixes: Eigen::Matrix<T,4,5> v; https://eigen.tuxfamily.org/dox/group__TutorialMatrixClass.html . However, I could not find for the vectors. Hence, I want to define a similar way for vectors but inside a template class, i.e., EigenVector as the same type T of its class as follows:

template <typename T>
class HagenDWT
{
 public:
   template <typename T, int Size> using EigenVector = Eigen::Matrix<T, Size, 1>;
   //rest of the code
 private:

 };

However, if I define EigenVector as:

template <typename M, int Size> using EigenVector = Eigen::Matrix<T, Size, 1>;

Everything works fine. I want to define EigenVector the same as its class type T. If it is possible could you suggest what to change?