Chapter 8 - Sequences and Infinite Series - 8.1 An Overview - 8.1 Exercises - Page 604: 3

$1, 2, 6, 24, 120$

For the first five terms, we need to find: $a_1, a_2, a_3, a_4$, and $a_5$ $a_1 = 1 $ by definition $a_{n+1} = na_n$ $a_1 = 1$ $a_2 = 2(1) = 2$ $a_3 = 3(2) = 6$ $a_4 = 4(6) = 24$ $a_5 = 5(24) = 120$