[math-fun] normal bases for GF(2^32)

I'm using the industry standard crc32 polynomial as my reduction polynomial. There appear to be only 6 monomials that generate normal bases: x^9, x^15, x^22, x^23, x^30, x^31. Is this number 6 approx. O(log 32), or is this number 6/32=19% "approximately" 100%-71%=29%. We can't worry about "optimal normal bases" here, because GF(2^32) can't have an optimal basis: * 32 can't have an optimal normal basis of type 1, since 2 is not a primitive element of GF(33). * 32 can't have an optimal normal basis of type 2, since 2*32+1=65 isn't prime.