C++ :

#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,sum=0;
	cin>>n;
	for(int i=1;i<=n;i++){
		sum=sum+i*(i+1);
	}
	cout<<sum<<endl;
	return 0;	
}

Python :

# coding=utf-8
n = int(input())
s = 0
for i in range(1,n+1):
    s+=i**2+i
print(s)