Chapter 11 - Sequences; Induction; the Binomial Theorem - Section 11.1 Sequences - 11.1 Assess Your Understanding - Page 827: 37

$a_1=-2 \\ a_2=0 \\ a_3 =3 \\ a_4 =7 \\ a_5 =12$

We are given that $a_n=n+a_{n-1}$ and $a_1=-2$. In order to determine the remaining values, we will have to substitute $n=2,3,4,5$ into the given sequence: $a_2=2+a_1=2+(-2)=0 \\ a_3=3+a_2=3+0 =3 \\ a_4=4+a_3=4+3=7 \\ a_5=5+a_4=5+7=12$