SAT Math Practice Question #26616 - SATify | SATify
#26616
number theory
modular arithmetic
binary representation
Relative Motion
hard
120 sec
Let x0,x1,x2,… be a sequence of numbers, where each xk is either 0 or 1. For each positive integer n, define Sn=∑k=0n−1xk2k. Suppose 3Sn≡1(mod2n) for all n≥1. What is the value of the sum x2022+2x2023+4x2024+8x2025?