6-3 编写函数计算Sn=a+aa+aaa+…+aa…a

以下是计算Sn=a+aa+aaa+...+aa...a的函数示例：

def calculate_Sn(a, n):
    Sn = 0
    for i in range(1, n+1):
        term = int(str(a) * i)
        Sn += term
    return Sn

a = 6
n = 3
result = calculate_Sn(a, n)
print("Sn =", result)  # 输出：Sn = 738