MATLAB中fibnum(n)函数的执行时间T(n)与n的函数关系是什么？

Question

function f = fibonacci(n)
%FIBONACCI Fibonacci sequence
% f = FIBONACCI(n) generates the first n Fibonacci numbers.

% Copyright 2014 Cleve Moler
% Copyright 2014 The MathWorks, Inc.
f = zeros(n,1);
f(1) = 1;
f(2) = 2;
for k = 3:n
f(k) = f(k-1) + f(k-2);
end

Answer 1

http://www.cnblogs.com/python27/archive/2011/12/09/2282486.html
时间复杂度是 O(n^3*2^n) （其中C是一个常数）