5
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1answer
516 views

Number of Permutations with k-inversions and with a single clamped value

This question is cross-posted from math.stackexchange because it might be too technical. Let $S_n$ be the symmetric group. Recall that the number of inversions of a permutation $\sigma\in S_n$ is the ...
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2answers
457 views

What is the expected number of increasing subsequence? [closed]

Given n numbers (each of which is a random integer, uniformly between 1~n), what is the expected number of increasing subsequences?