TITLE: How do you check if a sequence of numbers is truly random?
QUESTION [7 upvotes]: Suppose a source produces an indefinite sequence of positive integers. How can you check whether the numbers are generated truly randomly?

REPLY [2 votes]: Given some time dependent data-set, autocorrelation can be used to detect randomness and lack thereof. Take a look at for example http://en.wikipedia.org/wiki/Correlogram