9131098domain: NAppears in sequencesNumber of n X n 0..5 matrices whose square is also a 0..5 matrix.at n=3A213987T(n,k)=Number of n X n 0..k matrices whose square is also a 0..k matrix.at n=31A213990Number of 4X4 0..n matrices whose square is also a 0..n matrix.at n=4A213993