Answer
The first six terms are 1, 3, 7, 15, 31, and 63.
Work Step by Step
$a_{n}$=$2^{n}$-1
$a_{1}$=$2^{1}$-1 =1
$a_{2}$=$2^{2}$-1 =3
$a_{3}$=$2^{3}$-1 =7
$a_{4}$=$2^{4}$-1 =15
$a_{5}$=$2^{5}$-1 =31
$a_{6}$=$2^{6}$-1 =63
*To find a certain term, plug the number of the term in for 'n' and simplify.