Starting at 1 in binary and increasing the place value by 1 each time then converting to decimal?
Or it could just be multiplication by two.
1 x 2 = 2
2 x 2 = 4
4 x 2 = 8
8 x 2 = 16
16 x 2 = 32
32 x 2 = 64
64 x 2 = 128
128 x 2 = 256
256 x 2 = 512
512 x 2 = 1024
1024 x 2 = 2048
2048 x 2 = 4096