And so he said, if you start off with a male and a female, at the end of one month they have an offspring. Let's assume they have two offspring. At the end of the next month let's assume those offspring have offspring. Again a male and female.

在13世纪的时候想要计算兔子的数量,就是一个月大的兔子,再过一个月就可以进行交配,所以它说如果你一开始有一公一母两只兔子,在一个月末它们就可以生小兔子,让我们假设它们生了两只小兔子。

麻省理工公开课 - 计算机科学及编程导论课程节选

The question was how many rabbits do you have at the end of a year? At the end of two years? At the end of more than that number of years, and so. We can do this with the following level definition. We're going to let pairs of 0, the number of pairs at month 0, actually it would not be it would be 1.

在下一个月末的时候让我们假设,这2只小兔子也有了后代,同样是一公一母,问题是一年后你会有多少只小兔子？,两年后呢？更多年后呢？,我们可以用接下来的等级说明来解释，在第0个月有0对兔子。

麻省理工公开课 - 计算机科学及编程导论课程节选