text: #include <iostream>
  using namespace std;
  long long a[505];
  
  int main() {
  	a[1]=1;
  	for(int i=2;i<=501;i++) {
  		a[i]=a[i-1]+i*(i-1)/2+2*i-1;
  		int k=i-3,sum=0;
  		while(k>0) {
  			sum+=k;
  			k-=2;
  		}
  		a[i]+=sum;
  	}
  	int n;
  	while(cin>>n) {
  		cout<<a[n]<<endl;
  	}
  	return 0;
  } 