Given the formula:
[tex]a_n=n^2+2n+1[/tex]First term:
[tex]a_1=1^2+2(1)+1=1+2+1=4[/tex]Second term:
[tex]a_2=2^2+2(2)+1=4+4+1=9[/tex]Third term:
[tex]a_3=3^2+2(3)+1=9+6+1=16[/tex]Fourth term:
[tex]a_4=4^2+2(4)+1=16+8+1=25[/tex]Answer: the first four terms are: 4, 9, 16 and 25
