出这种题的意义是啥,还放在最后面100
等差数列
https://www.nowcoder.com/practice/f792cb014ed0474fb8f53389e7d9c07f
import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); int n = scanner.nextInt(); int count = 0; for (int i = 0, k = 2; i < n; i++, k += 3) { count += k; } System.out.println(count); } }