Write an algorithm to print a series of Roman numerals.
Implement roman_series(n), which returns a list containing the canonical Roman numeral representation of every integer from 1 through n, inclusive. For example, roman_series(5) returns ["I", "II", "III", "IV", "V"], and roman_series(10) ends with "X". The input is an integer from 1 through 3999; use subtractive notation such as IV, IX, XL, XC, CD, and CM.
def roman_series(n):