2001 AIME II Problem 3

Past Contests AIME 2001 AIME II
, , ,
1

Given that

\begin{aligned}& x_{1}=211 \\& x_{2}=375 \\& x_{3}=420 \\& x_{4}=523, \text { and } \\& x_{n}=x_{n-1}-x_{n-2}+x_{n-3}-x_{n-4} \text { when } n \geq 5\end{aligned}

find the value of x_{531}+x_{753}+x_{975}.