Hi, and thanks for your answer! I'm trying to compute the n-th iterate of a given differential expression and to find a closed formula for the coefficients involved. For example: What is the n-th iterate L^n[y] of L[y]:=y'''(x)+1/x^2 , where L^n:=L(L^(n-1)). To find a closed formula, I need to generate examples and keep track of the coefficients. It would be very helpful to get maple to do the following: when differentiating, say -2/x^3, I want it to return (-3)(-2)/x^4 rather than 6/x^4. Thanks again, Andrea

Hi, and thanks for your answer! I'm trying to compute the n-th iterate of a given differential expression and to find a closed formula for the coefficients involved. For example: What is the n-th iterate L^n[y] of L[y]:=y'''(x)+1/x^2 , where L^n:=L(L^(n-1)). To find a closed formula, I need to generate examples and keep track of the coefficients. It would be very helpful to get maple to do the following: when differentiating, say -2/x^3, I want it to return (-3)(-2)/x^4 rather than 6/x^4. Thanks again, Andrea