题解 | #尼科彻斯定理#

#include <stdio.h>

int main() {
    int m;
    while (scanf("%d", &m) != EOF) {
        int start = m * m - m + 1;
        printf("%d", start);
        for(int i = 1; i < m; i++) {
            printf("+%d", start + i * 2);
        }
        printf("\n");
    }
    return 0;
}