Sorry, I can't tell if you've written the equation as 2n²+1 or n²+1
If it's 2n²+1, substitute n for 9, as you want to find the 9th term of the sequence.
9²=81×2=164=1=165, so the 9th term is 165
If it's n²+1, substitute n for 9, as you want to find the 9th term of the sequence. 9²=81+1=82, so the 9th term is 83.