Unfortunately, that article misstates the relationship between ISO values. Powers of two are actually precise steps based on the cube root of 2, just like 1/3 step increments for aperture or shutter speed. They are only rounded off for the convenience for labeling lenses or shutter speed dials.
For example, lens apertures are rounded off from the series: 1.41, 2.00, 2.83, 4.00, 5.66, 8.00, 11.31, 16.00, 22.63, 32.00
But they are conventionally labeled: 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32
ISO values are actually:
31.50, 39.69 50.00, 63.00, 79.37, 100.00, 125.99, 158.74, 200.00, 251.98, 317.48, 400.00, 503.97, 634.96, 800.00
But they are conventionally given as:
32, 40, 50, 64, 80, 100, 125, 160, 200, 250, 320, 400, 500, 640, 800
And fractional shutter speeds follow the same series and convention as ISO values but expressed in the denominator as 1/30, 1/40, 1/50, 1/60
So equivalent offsetting incremental changes in ISO, shutter speed and aperture
should result in precisely the same exposure for the same lighting. But errors in actual shutter speed performance or imprecision in lens aperture adjustment (and possibly even sensor response) might produce slightly different exposures.