Fibonacci 8/23 Fibonacci

class Fibonacci
  def self.get_sequence(num)
    if num < 0
      raise ArgumentError.new("Fibonacci sequences must be >= 0")
    elsif num <= 2
      return [1] * num
    end

    seq = get_sequence(num - 1)
    return seq + [ seq[-2] + seq[-1] ]
  end
end