The smallest matrix is bounded by 2 for the lower PF and 6 for the upper PF with a Key Seed of 3. Key Seed is the smallest prime number in the seed list. With some exceptions, seed numbers are numbers discovered in prior matrices. Being the first matrix, this one does not have all the features of later matrices and not all the matrix rules apply. It is the only matrix that fails to obey the rules about seed numbers appearing in the first column prior to the matrix members. It is the only matrix with only one row. I have no excuse other than this is the first matrix and there may be a need for an initiation sequence that other matrices do not experience. Adding the lower PF of 2 to 1 generates 3 and again yields 5 for 2 members both of which are prime. Some might argue that the first matrix should be the number 2 but as it is a single number I have not have not regarded it as a full matrix.
