The radii of Sheffer functions over E(3)

If f is a two place function over E(k) that is either Sheffer or Sheffer with constants, then the radius of f is that least natural number r such that each two place function over E(k) can be defined as the composition of r or fewer copies of f. The radii of the 322 isotopy classes of Sheffer functions over E(3) are calculated. A sequence of useful conditions that a Sheffer function have small radius is developed; a sequence of useful conditions that a symmetric Sheffer function have small radius is developed