# MATLAB: How to solve a nested summation with recursive function

MATLABnested sumrecursiverecursive function

Hi,
I have a question related to solving a nested summation equation with a recursive function.
Suppose I have an equation of:
So, I tried to solve this problem by using a for loop to solve the summation equation and using a recursive function to expand the order of nested summation.
 test(3,0) function [sum] = test(a,b) sum = 0; for i=1:a-b    if a-b == 1        sum = 1;    else        sum = sum + (a-b) * test(a,b+i);    end end end
From the code I got
 ans = 9
I appreciate any help, thanks.

#### Best Answer

• I think your code is correct, and your calculation by hand is not.