Verified answer

take n=1 first

u will get 5(1)^2-2(1)-7=-4

take n=2

5(2)^2-2(2)-7=9

take n=3

5(3)^2-2(3)-7=32

take n=4

5(4)^2-2(4)-7=65

the first four terms are -4,9,32,65