Pretty much all the numbers can be explained as being the closest number to the geometric mean of the previous and following number. Once you have chosen to rou

Pretty much all the numbers can be explained as being the closest number to the geometric mean of the previous and following number. Once you have chosen to round the second number in E3 to 22, 47 is the closest to splitting 22 and 100 evenly. The exception is 33 in the E6 series, that should be 32 when splitting 22 and 47, most of the other "errors" in E12 and E24 are there because 33 pushes the other numbers upwards.