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 A145208 #5 Oct 13 2013 20:21:37 %S A145208 1,4,13,54,197,792,2977,11750,44744,175066,671783,2619148,10104590 %N A145208 Number of distinct shuffles of the identity permutation on n letters with the halfway-wrapped around permutation k+1,k+2,...,n-1,n,1,2,...,k where k=floor(n/2). %C A145208 A complicated formula has been found but needs to be simplified before entering here; also, a Maple program is on the way. %D A145208 C. Smith, dissertation, Harvard University, forthcoming. %e A145208 For n=2, the distinct shuffles of 12 with 21 are: 1221, 1212, 2112, 2121. %K A145208 nonn %O A145208 1,2 %A A145208 _Camillia Smith Barnes_, Oct 04 2008