First four terms are 7, -13, 67, -253
<em><u>Solution:</u></em>
Given that,
<em><u>The formula to find nth term is given as:</u></em>
We can find the first four terms by substituting n = 2, 3, 4
<em><u>First term:</u></em>
f(1) = 7
<em><u>Second term:</u></em>
Substitute n = 2
<em><u>Third term:</u></em>
Substitute n = 3
<em><u>Fourth term:</u></em>
Substitute n = 4
Thus first four terms are 7, -13, 67, -253