arithmetic progression
(亦作arithmetic series)
noun
1- a sequence of numbers in which each differs from the preceding one by a constant quantity (e.g. 1,2, 3,4, etc.; 9,7, 5,3, etc.)算术级数, 等差级数。
1.1
- mass noun the relation between numbers in such a sequence等差级数关系：
the numbers are in arithmetic progression.
这些数字按等差级数关系排列。