Represent Complex evaluation in a concise way?

So is it possible to let Mathcad represent the result in terms of even and odd cases?

Right now I only know to define n:=0,1..100 (for example)

Then write the complex equation and Mathcad will give a 100 by 1 vector (half of which are 1 and the other half are -1)

The result is not concise

Thank you in advance.

Shawn