Hi. I need some help with this problem. I have to solve

(1)

Using Frobenius method around zero. So proposing , differentiating and replacing in (1):

Regrouping and working a little bit this becomes:

I think this is fine, because the indicial equation I get gives the same roots from the other method:

Then

So I have:

And then

So for

The thing is I've tried some iterations but I can't get a expression for in terms of . How should I do this?

Bye there, thanks for your help.-