39 人解决，80 人已尝试。
56 份提交通过，共有 140 份提交。
5.1 EMB 奖励。
单点时限: 2.0 sec
内存限制: 256 MB
A double tower of hanoi contains 2n disks of n different sizes,two of each size.As usual,we’re required to move only one disk at a time,without putting a larger one over a smaller one.
What if we are required to reproduce the original top-to-bottom order of all the equal-size disks in the final arrangement?
There are so many tests.Each test have one interger n(1<=n<=60) represented the number of disks.
Output a single number of the minimum steps in a line.
1 5
3 123
39 人解决，80 人已尝试。
56 份提交通过，共有 140 份提交。
5.1 EMB 奖励。