Project Euler Problem 918
定义数列 \(\{a_{n}\}\) 满足 \(a_{1} = 1\), 对于 \(n \geqslant 1\) 有:
\[ \begin{aligned} a_{2n} &= 2a_n \\ a_{2n + 1} &= a_n - 3a_{n + 1} \end{aligned} \]定义数列 \(\{a_{n}\}\) 满足 \(a_{1} = 1\), 对于 \(n \geqslant 1\) 有:
\[ \begin{aligned} a_{2n} &= 2a_n \\ a_{2n + 1} &= a_n - 3a_{n + 1} \end{aligned} \]