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A260511 Number of signed permutations of length n that are sortable to the identity permutation by some sequence of cdr (context-directed reversal) moves. 1

%I

%S 1,3,15,120,1227,15188

%N Number of signed permutations of length n that are sortable to the identity permutation by some sequence of cdr (context-directed reversal) moves.

%H K. L. M. Adamyk, E. Holmes, G. R. Mayfield, D. J. Moritz, M. Scheepers, B. E. Tenner, and H. C. Wauck, <a href="http://arxiv.org/abs/1410.2353"> Sorting permutations: games, genomes, and cycles</a>, arXiv:1410.2353 [math.CO], 2014.

%e a(2) = 3 because [1,2], [-1,2], and [1,-2] are sortable to the identity [1,2] using only context-directed reversal moves.

%Y A249165 gives the number of unsigned permutations sortable by context-directed swaps; this is the analog for signed permutations and context-directed reversals.

%Y A260506 gives the number of signed permutations sortable by both cdr and cds moves together. This sequence is therefore always bounded by A260506.

%Y A000165 counts the total number of signed permutations.

%K nonn,more

%O 1,2

%A _Caleb Stanford_, Jul 27 2015

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Last modified November 19 08:44 EST 2019. Contains 329318 sequences. (Running on oeis4.)