题解 | #等差数列#
等差数列
https://www.nowcoder.com/practice/f792cb014ed0474fb8f53389e7d9c07f
import java.util.Scanner;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
while (sc.hasNext()){
int n = sc.nextInt();
int sum = 0;
for (int i = 2; i < 2+(n*3); i=i+3) {
sum +=i;
}
System.out.println(sum);
}
}
}