Great idea Bill. I like playing with gear ratios and have calculated:
1) A nearly perfect half step is 46-49,
2) A nearly perfect 1.5 step is 38-46, and
3) If you could get a 15-16 double cog on a Rohloff, that is also an almost perfect half step (if that is what you would call it).
I can just imagine 28 gears with an even 6.6% step between each gear. This change is equivalent to the 15-16 change on your rear cog. You could find the perfect gear for almost any condition and no crazy shift patterns either.