推了几次终于推出关系,可是结果就是不对, 一看前辈的帖子,原来n==0是1结果就完全对了!
		dp[0] = 1; dp[2] = 3;
		for(int i = 2; i <= n; i+=2)
		{
			dp[i] = dp[i-2];
			for(int j = 0; j <= i-2; j+=2)
				dp[i] += 2*dp[j];
		}