What is the common difference of 1, 2, 4, 8, 16,...?

This sequence has a common ratio (##2##), rather than a common difference. It is a geometric sequence, not an arithmetic one.

have a common difference. That is, the difference between any two consecutive terms is constant.

For example:

##5, 8, 11, 14, 17##

is an arithmetic sequence with common difference ##3##.

We note that:

##8-5 = 11-8 = 14-11=17-14 = 3##

##color(white)()## have a common ratio. That is, the ratio between any two consecutive terms is constant.

For example:

##1, 2, 4, 8, 16##

is a geometric sequence with common ratio ##2##.

We note that:

##2/1 = 4/2 = 8/4 = 16/8 = 2##

##color(white)()## The infinite sequence ##1, 2, 4, 8, 16,...## is a geometric sequence if it continues in similar fashion in the "...", doubling every step.