级数

(math.) series

level / grade / rank / step (of stairs) / CL:個|个[ge4] / classifier: step, level

to count / to count as / to regard as / to enumerate (sb's shortcomings)

number / figure / several / CL:個|个[ge4]

frequently / repeatedly

geometric series

geometric series (such as 1+2+4+8+...)

convergent series (math.)

arithmetic series (such as 2+4+6+8+...)

arithmetic series (such as 2+4+6+8+...)

power series (math.)

exponential increase