Chapter 11 - Sequences; Induction; the Binomial Theorem - Section 11.1 Sequences - 11.1 Assess Your Understanding - Page 827: 15

The first five terms are: $s_1= 1\\ s_2=2 \\ s_3=4 \\s_4=4 \\s_5 =5$

We are given that {$s_n$} $=n$ In order to determine the first five terms, we will have to substitute $n=2,3,4,5$ into the given sequence {$s_n$}: $s_1= 1\\ s_2=2 \\ s_3=4 \\s_4=4 \\s_5 =5$