Is a random string a good verification code

I'm generating a verification code to be used for account activation. You've probably seen this sort of thing before.

My question: if I were to generate this code with a complex formula like this:

md5(md5(time().'helloguys'.rand(0,9999)));

Is it really any better than generating just a random string of 32 characters and numbers like gj3dI3OGwo5Enf...?