了解太少了
RSolve[{f[x + 1] + f[x - 1] == 3 f[x], f[1] == 3/2, f[0] == 1}, f[x], x] // FullSimplify
Mathematica的RSolve还能这样
原文：http://blog.csdn.net/stereohomology/article/details/44685407
