MathDB
Terms of a Sequence

Source:

December 28, 2006

Problem Statement

Given that \begin{align*} 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{align*}
find the value of x531+x753+x975x_{531}+x_{753}+x_{975}.