The rule of "rabbit sequence" is Fibonacci sequence principle, which refers to such a sequence: 0, 1, 1, 2, 3, 5, 8, 13, 2 1, 34, ... Mathematically, Fibonacci sequence is based on F(n)=F(n - 1)+F(n - 2)(n？ ≥ 2，n？ ∈ N*).

Fibonacci sequence has direct applications in modern physics, quasicrystal structure, chemistry and other fields. Therefore, the American Mathematical Society published a mathematical magazine named Fibonacci Series Quarterly from 1963, and devoted itself to publishing the research results in this field.

Extended data:

Such a series is a natural number, but the general formula is expressed by an irrational number. When n approaches infinity, the ratio of the former term to the latter term approaches the golden section of 0.6 18 (or the fractional part of the ratio of the latter term to the former term approaches 0.6 18).

The further back,

The closer the ratio is to the golden ratio.

Baidu encyclopedia-Fibonacci sequence