The integers $1, 2,. . . , n$ are arranged in order so that each value is strictly larger than all values above or is strictly less than all values previous. In how many ways can this be done?
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Tags: combinatorics
The integers $1, 2,. . . , n$ are arranged in order so that each value is strictly larger than all values above or is strictly less than all values previous. In how many ways can this be done?