急求：用C#而不是求C++编写一个程序，计算s=1+(1+2)+(1+2+3)+…+(1+2+3+4+5+…+n)的代码多谢大家

Answer 1

static void Main(string[] args)
{
Console.WriteLine("请输入一个整数：");
int n = Convert.ToInt32(Console.ReadLine());
int temp = 0; int sum = 0;
for (int i = 1; i <= n; i++)
{
temp += i;
sum += temp;
}
Console.WriteLine("结果是: {0}", sum);
Console.ReadKey();
}

Answer 2

sum=0;
for(i=1;i<=n;i++);
sum=i*n-(i-1)+sum;