# Discrete convolution sum help

#### kaiosama

Joined Dec 6, 2010
29
Hello everyone, I'm trying to compute this discrete convolution, but apparently it's wrong and I don't really know why...

#### steveb

Joined Jul 3, 2008
2,436
Your upper limit on the summation looks wrong. The upper limit will depend on n. The mistake was substituting k=2 into your second constraint equation.