Answer
The first six terms are -$\frac{1}{2}$, 3. 12$\frac{1}{2}$, 31, 61$\frac{1}{2}$, and 215.
Work Step by Step
$a_{n}$=$\frac{1}{2}$$n^{3}$-1
$a_{1}$=$\frac{1}{2}$$(1)^{3}$-1 =-$\frac{1}{2}$
$a_{2}$=$\frac{1}{2}$$(2)^{3}$-1 =3
$a_{3}$=$\frac{1}{2}$$(3)^{3}$-1 =12$\frac{1}{2}$
$a_{4}$=$\frac{1}{2}$$(4)^{3}$-1 =31
$a_{5}$=$\frac{1}{2}$$(5)^{3}$-1 =61$\frac{1}{2}$
$a_{6}$=$\frac{1}{2}$$(6)^{3}$-1 =215
*To find a certain term, plug the number of the term in for 'n' and simplify.