#### Answer

The first five terms are:
$a_1 = 6$
$a_2 = 8$
$a_3 = 12$
$a_4 = 20$
$a_5 = 36$
The sequence has no common difference so it is not arithmetic.

#### Work Step by Step

Find the first five terms by substituting 1, 2, 3, 4 and 5 to $n$ in the given formula.
$a_1 = 4+2^1=4+2=6$
$a_2 = 4+2^2=4+4=8$
$a_3 = 4+2^3=4+8=12$
$a_4 = 4+2^4 = 4+16=20$
$a_5 = 4+2^5 = 4+32=36$
A sequence is arithmetic if there exists common difference among consecutive terms. The sequence has no common difference so it is not arithmetic.