Fibonacci Sequence Constants

The Fibonacci numbers are defined recursively by the equation \[ F_n = F_{n - 1} + F_{n - 2}\]for every integer $ n \ge 2 $, with initial values $ F_0 = 0 $ and $ F_1 = 1 $. Let $ G_n = F_{3n} $ be every third Fibonacci number. There are constants $ a $ and $ b $ such that every integer $ n \ge 2 $ satisfies \[ G_n = a G_{n - 1} + b G_{n - 2}.\]Find $ (a,b) $.

  • 1
  • 2
  • 3
  • +
  • 4
  • 5
  • 6
  • -
  • 7
  • 8
  • 9
  • $\frac{a}{b}$
  • .
  • 0
  • =
  • %
  • $a^n$
  • $a^{\circ}$
  • $a_n$
  • $\sqrt{}$
  • $\sqrt[n]{}$
  • $\pi$
  • $\ln{}$
  • $\log$
  • $\theta$
  • $\sin{}$
  • $\cos{}$
  • $\tan{}$
  • $($
  • $)$
  • $[$
  • $]$
  • $\cap$
  • $\cup$
  • $,$
  • $\infty$