MathDB
2018-2019 Fall OMO Problem 27

Source:

November 7, 2018
Online Math Open

Problem Statement

Let p=216+1p=2^{16}+1 be a prime. Let NN be the number of ordered tuples (A,B,C,D,E,F)(A,B,C,D,E,F) of integers between 00 and pāˆ’1p-1, inclusive, such that there exist integers x,y,zx,y,z not all divisible by pp with pp dividing all three of Ax+Ez+Fy,By+Dz+Fx,Cz+Dy+ExAx+Ez+Fy, By+Dz+Fx, Cz+Dy+Ex. Compute the remainder when NN is divided by 10610^6.
Proposed by Vincent Huang