A191247 - OEIS

%I #5 Mar 30 2012 17:36:33

%S 0,1,2,0,2,1,3,1,0,1,3,0,3,1,2,3,2,0,2,3,0,3,2,1,4,1,2,4,2,1,0,1,2,0,

%T 2,1,4,1,0,1,4,0,4,1,2,4,2,0,2,4,0,4,2,1,3,1,4,1,3,4,3,1,0,1,3,0,3,1,

%U 4,1,0,1,4,0,4,1,3,4,3,0,3,4,0,4,3,1,2,3,2,4,2,3,4,3,2,0,2,3,0,3,2,4,2,0,2,4,0,4,2,3,4,3,0,3,4,0,4,3,2,1,5,1

%N First element in permutations in cool-lex ordering.

%C Start with the identical permutation [0,1,2,...,n-1] and obtain the next permutation by finding the element a(n) (n>=1) and cyclically shifting the prefix ending in a(n) by one position to the right (see right column in example for A191246).

%D Aaron Williams, Loopless Generation of Multiset Permutations using a Constant Number of Variables by Prefix Shifts, ACM-SIAM Symposium on Discrete Algorithms (SODA09), (2009), see link.

%H SODA 2009 proceedings with Williams' paper: <a href="http://www.siam.org/proceedings/soda/2009/soda09.php">SIAM: Proceedings of the Twentieth Annual ACM-SIAM Symposium on Discrete Algorithms</a>.

%e (see A191246).

%Y A191246 (size of shifted prefixes).

%K nonn

%O 0,3

%A _Joerg Arndt_, May 28 2011