Loops

import java.util.Scanner;

public class Loops {

	public static void main(String[] args) {
		
        Scanner scan = new Scanner(System.in);
        long n = scan.nextLong();	   
		//long n = 5000000000l;
	    System.out.println(calculate2(n));
	    //System.out.println(calculate2(n));
//	    scan.close();

	}
	
	public static long calculate(long n) {
		return (long) ( (Math.pow(n, 3) / 6.0 ) + (Math.pow(n, 2) / 2.0 ) + ( n/ 3.0 ) );
	
	}
	
	public static long calculate2(long n) {
		return (n*(2l + n*(n + 3l))) / 6l;
	}
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED