For the problem presented, this is what it would look like if you combine the terms of the series 2c0x0+2c2x0+∑n=1∞[an+2(n+1)(n+2)−ann−2an]=0
And then…
2c0 + 2c2 = 0 and c2 = −c0
So it would go something like this.
Y = (1 − x2) c0
I am hoping that this answer has satisfied your query about this specific question.