harmonic progression

harmonic-progression的词性：
n.Mathematics （名词）【数学】

1. A sequence of quantities whose reciprocals form an arithmetic progression, such as 1, ^!/3, ^!/5, ^!/7, . . . .
调和级数：其倒数形成代数级数的量的序列，例如1，^!/3，^!/5，^!/7…