The first term of the sequence is -3.
According to the formula each next term will be obtained by multiplying the previous term by 2.
So, next terms will be:
Second term = 2 x First Term = 2 x (-3) = - 6
Third term = 2 x (-6) = -12
Fourth term = -24
Fifth term = -48
Sixth term = -96
So, the sequence will be:
-3, -6, -12, -24, -48, -96 ...