MathDB
p^3|(kp choose k)-k

Source: Bulgaria 1991 P3

June 2, 2021
number theory

Problem Statement

Prove that for every prime number p5p\ge5,
(a) p3p^3 divides (2pp)2\binom{2p}p-2; (b) p3p^3 divides (kpp)k\binom{kp}p-k for every natural number kk.