A263929 Number of permutations that are sortable with two stacks in series.

1, 1, 2, 6, 24, 120, 720, 5018, 39374, 337816, 3092691, 29659731, 294107811, 2988678546, 30935695794, 324832481490, 3450158410649, 36993206191004, 399827092167771, 4351269802153188

Offset

0,3

Links

Table of n, a(n) for n=0..19.

Andrew Elvey-Price, Anthony J Guttmann, Permutations sortable by two stacks in series, arXiv:1510.08663 [math.CO], (29-October-2015)

Crossrefs

Sequence in context: A177541 A177551 A177535 * A324139 A324138 A324137

Adjacent sequences: A263926 A263927 A263928 * A263930 A263931 A263932

Keyword

nonn

Author

Joerg Arndt, Oct 30 2015

Status

approved