Every term is four times the last. Using this, we see that:
5th term: 192*4=768
6th term: 768*4=3072
7th term: 3072*4=12288
Note that technically, we're making an educated guess that this is the method the sequence is generated. Just having four terms is not enough to PROVE that this is the case, but multiplying by four is by far the most likely sequence.
