lǎo / shī / yòng / shù / liè / jǔ / lì / shuō / míng / rú / hé / lì / yòng / dì / tuī / guān / xi / jì / suàn / měi / yī / xiàng老师用数列举例,说明如何利用递推关系计算每一项。The teacher used a sequence as an example to explain how to calculate each term using a recurrence relation.