黄金比
When any log-linear factor is ranked, the ranks follow the Lucas numbers, which consist of the sequentially additive numbers 1, 3, 4, 7, 11, 18, 29, 47, 76, 123, 199, etc. Like the more famous Fibonacci sequence, each number is approximately 1.618 (the Golden ratio) times the preceding number. For example, the third term in the sequence above, 4, is approximately 1.6183, or 4.236; the fourth term, 7, is approximately 1.6184, or 6.854; the eighth term, 47, is approximately 1.6188, or 46.979. With higher values, the figures converge. An equiangular spiral is sometimes used to visualize such sequences.