[math-fun] Arndt bit reversal 32 request

Observe that 32 = 12 + 8 + 12. 1.Reverse all runs of 4 bits. 2.Now reverse each of the 8, the 12, and the 12 by swapping their first with their last nybbles. 3.Finally swap the 12 & 12. How's that do? [Similarly 16=6+4+6 and 64=24+16+24.]