We have, $a_n$ = n (n + 2) Substituting n = 1, 2, 3, 4, 5, we get $a_1$ = 1 (1 + 2) = 1 × 3 = 3 $a_2$ = 2 (2 + 2) = 2 × 4 = 8 $a_3$ = 3 (3 + 2) = 3 × 5 = 15 $a_4$ = 4 (4 + 2) = 4 × 6 = 24 $a_5$ = 5 (5 + 2) = 5 × 7 = 35 ∴ The first five terms are 3, 8, 15, 24 , 35.