Abstract

We investigate when the sequence of binomial coefficients binom(k,i) modulo a prime p, for a fixed positive integer k, satisfies a linear recurrence relation of (positive) degree h in the finite range 0⩽i⩽k. In particular, we prove that this cannot occur if 2h⩽k<p−h. This hypothesis can be weakened to 2h⩽k<p if we assume, in addition, that the characteristic polynomial of the relation does not have −1 as a root. We apply our results to recover a known bound for the number of points of a Fermat curve over a finite field.