How do i find if a number is not random ?

[papa smurf]

giving a drawing of lets say numbers 1-10 over a number of draws how can i find if the drawing is not random.

[kureido]

Assuming that you're asking about randomness defined as each number having an equal probability of being drawn, a histogram of a statistically significant sample should reveal roughly equal numbers of draws of each number, just as flipping a coin enough times should reveal that each side shows up roughly 50% of the time.

If you're asking if a random number generator is *random* or *pseudo-random*, i.e., the next number drawn is or is not dependant on previous draws, a non-random seed, etc., that's a whole other story, and a lot more complicated to determine.

-b

[SumZero]

You can never know for sure. But there are tests you can run that determine how likely the pattern is to have been randomly generated by testing various distributions on the numbers. See things like csrc.nist.gov/rng/nissc-paper.pdf and http://www.ciphersbyritter.com/NEWS2/TESTSBBS.HTM.