算术级数：一个数量在其变化的过程中，每一次变化后的量是变化前的若干倍，也就是乘积的关系。

Arithmetic progression: a number of its change in the process, after each change in the amount of change several times before, that is the product of the relationship.

youdao

算术级数：一个数量在其变化的过程中，每一次变化后的量是变化前的若干倍，也就是乘积的关系。

Arithmetic progression: a number of its change in the process, after each change in the amount of change several times before, that is the product of the relationship.

youdao