http://acm.hdu.edu.cn/showproblem.php?pid=2139
代码：
#include <bits/stdc++.h>
using namespace std;
const int maxn = 2345;
long long s[maxn];
int main() {
int N;
s[1] = 1;
for(int i = 3; i <= maxn; i += 2)
s[i] = s[i - 2] + i * i;
while(~scanf("%d", &N)) {
printf("%lld\n", s[N]);
}
return 0;
}
HDU 2139 Calculate the formula
原文：https://www.cnblogs.com/zlrrrr/p/9686151.html