22159 牛牛学数列4
牛牛学数列4
https://ac.nowcoder.com/acm/problem/22159
#include<bits/stdc++.h>
using namespace std;
int main()
{
int n,a,b,i,j;
cin>>n;
for(i=1;i<=n;i++)
{
b=0;
for(j=1;j<=i;j++)
b+=j;
a+=b;
}
cout<<a<<endl;
return 0;
}
