Answer: 2n^2+3n-4
1st differnce is 3, 7, 11, 15
2nd differnce is 4
so its 2n^2
we compare it to teh 2n^2 sequence
2 8 18 32 50
-1 2 9 20 35
difference is 3, 6, 9, 12,15
so it is 3n-4
