Base 2 Log Scale Axis

I've got a column chart plotting # of cases run at different parallel scales. In general the number of cores you use works on a base 2 scale.

Data might look like the following... When this is plotted as "Count of Cases by Cores" on a Log-X-Axis, the values don't cluster well with the vertical ticks - as the section are 1-10, 10-100, 100-1000. I'd like the axis to be log-scale but base 2... So the axis values read 1-2-4-8-16-32-64 (or perhaps with the below data, values might be 1-8-64-512-4096 but things would land on the vertical lines splitting the X-axis, rather than being awkwardly spread around them.

# Cores | # Cases

     1      |     300

     2      |     190

     4      |     520

     8      |     100

   16      |     460

   32      |     350

   64      |     800

 128      |     920

 256      |     310

 512      |     290

1024     |     550

2048     |     630

4096     |     120