A193938 3-nonnesting permutations.

1, 2, 6, 24, 118, 675, 4333, 30464, 230615, 1856336, 15738672, 139509303, 1285276242, 12248071935, 120255584181, 1212503440774, 12519867688928, 132079067871313, 1420723274988736, 15554956521285848

Offset

1,2

Comments

Also the number of 3-noncrossing permutations.

Links

Table of n, a(n) for n=1..20.

Sophie Burrill, Sergi Elizalde, Marni Mishna and Lily Yen, A generating tree approach to k-nonnesting partitions and permutations, arXiv preprint arXiv:1108.5615 [math.CO], 2011-2014.

S. Corteel, Crossings and alignments of permutations, Adv. Appl. Math 38 (2007) 149-163.

Crossrefs

Cf. A193935, A193936, A193937.

Sequence in context: A224295 A263777 A088713 * A298432 A336072 A328501

Adjacent sequences: A193935 A193936 A193937 * A193939 A193940 A193941

Keyword

nonn,more

Author

Lily Yen, Aug 09 2011

Status

approved