I bet someone knows who the prover is. (But remarkable, really!) On Wed, Oct 24, 2018 at 8:03 PM Allan Wechsler <acwacw@gmail.com> wrote:
At http://mathsci.wikia.com/wiki/The_Haruhi_Problem, we have an intriguing situation.
The problem is, what is the shortest string that contains every permutation on N letters as a substring.
The problem has been around for a while, but somebody posted it on Wikia, a wiki dedicated to fans of various TV programs, mostly anime.
Then an anonymous commenter posted a proof of a lower-bound that had been conjectured earlier, that the shortest string must have length at least n! + (n-1)! + (n-2)! + n - 3, for n > 2. The style is a little bit amateurish but the proof seems correct. Robin Houston, a mathematician who has worked on the problem, has vetted it.
Nobody knows who the prover is. _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com https://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
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