Answer
$30$
Work Step by Step
Given that $
a_n=(n-1)^2
$ then the first 5 terms are
\begin{array}{l}
a_1=(1-1)^2\\
a_1=(0)^2\\
a_1=0
,\\\\
a_2=(2-1)^2\\
a_2=(1)^2\\
a_2=1
,\\\\
a_3=(3-1)^2\\
a_3=(2)^2\\
a_3=4
,\\\\
a_4=(4-1)^2\\
a_4=(3)^2\\
a_4=9
,\\\\
a_5=(5-1)^2\\
a_5=(4)^2\\
a_5=16
.\end{array}
Hence, the sum is $
0+1+4+9+16
=
30
.$