Is a random string a good verification code

[Fgeragep]

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: \[code\]md5(md5(time().'helloguys'.rand(0,9999)));\[/code\]Is it really any better than generating just a random string of 32 characters and numbers like \[code\]gj3dI3OGwo5Enf...\[/code\]?