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A342140 Number of permutations of degree n with greatest sum of distances and highest Shannon entropy. 1
1, 1, 3, 2, 17, 4, 86, 4, 488, 12, 3172, 40, 22912, 56, 166814, 256 (list; graph; refs; listen; history; text; internal format)



Starting from a list of n ordered numbers, the sequence gives the number of permutations of the list that display both the greatest sum of distances (see A007590 and A062870) and the highest Shannon entropy (see A341838 for a more in-depth explanation on how to calculate it).

A way to interpret this is to see these permutations as the ones with both the highest level of disorder and the greatest distance from a starting configuration.


Table of n, a(n) for n=1..16.

Andrea G. Amato How well can you shuffle a deck of cards?

Andrea G. Amato, Conjectures and properties


Starting from (1,2,3,4), there are only two permutations that have both the greatest sum of distances (which is 8 for n=4) and the highest Shannon entropy (which is 1.039720... for n=4). These permutations are (3,4,2,1) and (4,3,1,2).


Cf. A007590 (greatest sum of distances of a given n).

Cf. A062870 (permutations that possess this property).

Cf. A341838 (number of permutations with the highest Shannon entropy).

Sequence in context: A209600 A072045 A189731 * A126354 A158939 A173795

Adjacent sequences:  A342137 A342138 A342139 * A342141 A342142 A342143




Andrea G. Amato, Mar 01 2021


a(13)-a(15) from Hugo Pfoertner, Mar 02 2021

a(16) from Hugo Pfoertner, Mar 07 2021



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Last modified September 28 18:42 EDT 2021. Contains 347717 sequences. (Running on oeis4.)