cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A049206 Maximum mean distance between cards during perfect faro shuffles, with cut, to return to original order in A024222.

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%I A049206 #8 Apr 30 2014 01:29:19
%S A049206 0,1,1,2,3,3,3,4,5,5,5,6,7,7,7,8,9,9,9,10,11,11,11,12,13,13,13,14,15,
%T A049206 15,15,16,17,17,17,18,19,19,19,20,21,21,21,22,23,23,23,24,25,25,25,26,
%U A049206 27,27,27,28,29,29,29,30,31,31,31,32,33,33,33,34,35,35,35,36,37,37,37
%N A049206 Maximum mean distance between cards during perfect faro shuffles, with cut, to return to original order in A024222.
%F A049206 Take difference between successive cards after each shuffle. Compute mean (if necessary, round to nearest integer). Retain until replaced by a higher mean in a succeeding shuffle.
%F A049206 (1/4) {2n + 2 - (-1)^[n/2] + (-1)^[(n-1)/2] }. - _Ralf Stephan_, Jun 10 2005
%F A049206 a(n)=A004525(n), n>1. [From _R. J. Mathar_, Oct 15 2008]
%e A049206 Consider n=6. There are 4 shuffles to return to original order in a 6-card deck. The maximum mean distance between cards during these 4 shuffles and cuts, s1-s4, is 3, computed as follows: s1, 415263, cut, 263415; s2, 421653, cut 653421; s3, 462513, cut 513462; s4, 456123, cut, 123456. Mean distances: s1 15/5=3, maximum; s2 7/5=1.4; s3 13/5=2.6; s4 5/5; mean cumulative distance: 40/20=2.
%Y A049206 Cf. A024222, A024542.
%K A049206 easy,nonn
%O A049206 1,4
%A A049206 _Enoch Haga_