Codeforces 1353 C. Board Moves

找规律递推。

AC代码：

const int N = 5e5 + 50;
int n, m, k;
ll a[N];
int main()
{
     
	int t;
	sd(t);
	a[1] = 0;
	for (ll i = 3, j = 1; i <= N - 10; i += 2, j++)
		a[i] = a[i - 2] + 4 * (i - 1) * j;
	while (t--)
	{
     
		sd(n);
		pld(a[n]);
	}
	return 0;
}