Power Series Problem: Am I Correct?

[temaire]

Homework Statement

Well, I'm not getting any problems from the question, but there is a part of the solution that I don't agree with.

Here's the problem statement:
[PLAIN]http://img810.imageshack.us/img810/5387/powerseriesproblem.png

Here's part of the solution:
[PLAIN]http://img38.imageshack.us/img38/2104/powerseries.png

The Attempt at a Solution

As you can see, in the solution I circled +1 in red. I don't think it should be there. Instead, I think outside the right square bracket there should be + a_n

Am I correct?

 

[vela]

I agree with you. Looks like there's a mistake in the solutions.