import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
int n = in.nextInt();
int a = 0;
for (int i=1;i<=n;i++){
a+=(n+1-i)*i ;
}
System.out.println(a);
}
} import java.util.*;
public class Main {
public static void main(String[] arg) {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int sum1 = 0;
int sum2 = 0;
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= i; j++) {
sum1 += j;
}
sum2 += sum1;
}
System.out.println(sum1);
}
} import java.util.*;
public class Main {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
while(scanner.hasNext()){
int num = scanner.nextInt();
int beforeSum = 0;
int allSum = 0;
for(int i = 1;i <= num;i++){
beforeSum = beforeSum + i;
allSum = allSum + beforeSum;
}
System.out.println(allSum);
}
}
}