#include <stdio.h>
int f(int n)
{
	if (n == 1)
	{
  		return 1;
	}
	return f(n-1)+n*n;
}

int main()
{
	int n;
	while (scanf("%d", &n) == 1)
	{
 		printf("%d\n", f(n));
	}
	return 0;
}