Yep that's a definition. I'm not sure why you quoted it?
You can make all kinds of arguments to remove any number, but which one leaves a sequence with minimal kolmogorov complexity? Which one leaves a sequence where you can predict the next number?
"Which one leaves a sequence where you can predict the next number?"
Who said you had to predict the next number? If the question asked "Fill in the next number in this sequence" then I'd agree with you, but instead it asked which number didn't belong.
It's a heuristic. If you can't explain the series then you lose a lot of points in arguing that you interpreted it correctly.
Remember, the question isn't asking you to sort a bag of numbers into piles, it's giving them in a specific order and asking which list of n-1 numbers in that order is most coherent.
"is most coherent"
Of course it's clear which is most coherent, but what I'm trying to illustrate is how less obvious approaches may still demonstrate intelligence, I'll look up some more IQ test questions and find a different example to do this...
EDIT: Found one that should be better. What is your answer to this question... http://imgbox.com/a7vshE9u
Well there's one interpretation with three answers that doesn't use the info presented, and there's another interpretation with one answer that does use the info presented... 8
So I see your point about figuring out what the examiner wants and I think it makes the question better since you can't blindly run with a first interpretation and ignore half the question.
(Is that a real IQ test? I'm not trying to say it isn't, just that "internet IQ test" is not a trustworthy phrase.)
You can make all kinds of arguments to remove any number, but which one leaves a sequence with minimal kolmogorov complexity? Which one leaves a sequence where you can predict the next number?