Question 977535
<pre>
Here are two examples of geometric series' with R=-1 and the number
of terms N is odd:

2,-2,2,-2,2,-2,2

The nth or 7th term, 2, is the same as the first term, 2.

Another example

-8,8,-8,8,-8

The nth or 5th term, -8, is the same as the first term, -8.

That'll always be the case.

Edwin</pre>