
ZOJ Problem Set  2547
In how many ways can you tile a 3xn rectangle with 2x1 dominoes? Here is a sample tiling of a 3x12 rectangle.
InputInput consists of several test cases followed by a line containing 1. Each test case is a line containing an integer 0 ≤ n ≤ 30.OutputFor each test case, output one integer number giving the number of possible tilings.Sample Input2 8 12 1 Sample Output3 153 2131 Source: University of Waterloo Local Contest 2005.09.24 