Permutation binomial functions over ßnite Gelds
We consider binomial functions over a finite field of order 2<sup>n</sup>. Some necessary condition is found for such a binomial function to be a permutation. It is proved that there are no permutation binomial functions in the case that 2<sup>n</sup> - 1 is prime. Permutation binomial functions are constructed in the case when n is composite and found for n ≤ 8. Tab. 2, bibliogr. 30.