Moving in the matrix

Imagine I have a 4x4 chess board. How can I define the movements of the knight in this board?

Answer 1

[Walter Roberson]

(I,J) -> 
  (I-1,J-2)
  (I-1,J+2)
  (I+1,J-2)
  (I+1,J+2)
  (I-2,J-1)
  (I-2,J+1)
  (I+2,J-1)
  (I+2,J+1)

and then filter out the ones that went out of bounds.