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.
%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_