如何在字符串中找到至少重复一次的最大序列？

def find_max_repeated_sequence(s):
    n = len(s)
    dp = [[0] * n for _ in range(n)]
    max_len = 0
    end_index = 0
    for i in range(n):
        for j in range(i+1, n):
            if s[i] == s[j]:
                dp[i][j] = dp[i+1][j-1] + 1
                if dp[i][j] > max_len:
                    max_len = dp[i][j]
                    end_index = j
            else:
                dp[i][j] = 0
    start_index = end_index - max_len + 1
    return s[start_index:end_index+1]