# Complex Algorithms

Level pending

An algorithm takes a number, $$N$$, and returns a list of numbers, all divisors of $$N$$. You may have ideas on how to implement such a problem, but you observe the following runtimes as $$N$$ grows. Which of these runtimes is the best upper bound for the algorithm?

 $$N$$ Runtime (seconds) 3 1 6 4 9 9 12 16
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