The pattern is that it multiplies the previous term by 4. So 2 x 4 is 8, 8 x 4 is 32, 32 x 4 is 128 and so on and so forth.
128 x 4 is 512. This is your next term
512 x 4 is 2048. This is the next term after that.
2048 x 4 is 8192. This is your final term.
I think we just figured out how the game 2048 works :P