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The number of rooted trees (NR) for n taxa is ______

The number of rooted trees (NR) for n taxa is ______ Correct Answer NR = (2n− 3)!/2n−2 (n− 2)!

The number of potential tree topologies can be enormously large even with a moderate number of taxa. The increase of possible tree topologies follows an exponential function. In this formula, (2n−3)! Is a mathematical expression of factorial, which is the product of positive integers from 1 to 2n − 3. For example, 5! = 1 × 2 × 3 × 4 × 5 = 120.

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