a1 = -3, an = 2∙an-1

Let n = 2

a2 = 2∙a2-1
a2 = 2∙a1
a2 = 2∙(-3)
a2 = -6

Let n = 3

a3 = 2∙a3-1
a3 = 2∙a2
a3 = 2∙(-6)
a3 = -12

Let n = 4

a4 = 2∙a2-1
a4 = 2∙a1
a4 = 2∙(-12)
a4 = -24

So far we have only four terms: -3, -6, -12, -24, __, __

Now you finish. Let n = 5 and n = 6 to find the 
remaining two terms you were to find. 

Edwin