序列中出现的次数最多

def find_most_frequent(sequence):
    count_dict = {}
    for element in sequence:
        if element in count_dict:
            count_dict[element] += 1
        else:
            count_dict[element] = 1
    
    max_count = 0
    most_frequent_element = None
    for element, count in count_dict.items():
        if count > max_count:
            max_count = count
            most_frequent_element = element
    
    return most_frequent_element

# 示例用法
sequence = [1, 2, 3, 4, 2, 2, 3, 3, 3, 4, 4, 4, 4]
most_frequent = find_most_frequent(sequence)
print("序列中出现次数最多的元素是:", most_frequent)