View Compilation Error

0_0_4143915_16905\Main.java:14: 不是语句
            System.out.println( (n + 1) * n)/2 + "\n");
                                               ^
0_0_4143915_16905\Main.java:14: 需要 ';'
            System.out.println( (n + 1) * n)/2 + "\n");
                                                     ^
2 错误