The first four terms
an1 = 3n^2 -7 = 3(1)^2 -7 = 3(1)-7 = -4an2 = 3n^2 -7 = 3(2)^2 -7 = 3(4)-7 = 5an3 = 3n^2 -7 = 3(3)^2 -7 = 3(9)-7 = 20an4 = 3n^2 -7 = 3(4)^2 -7 = 3(16)-7 = 41