A215257 Number of indecomposable permutations sortable by a double-ended queue.

0, 1, 1, 3, 13, 67, 383, 2345, 15069, 100341, 686515, 4797997, 34110765, 245926667, 1793867881, 13214905229, 98177212059, 734746226575, 5534054981071, 41917876423855, 319102504087883, 2440086947417629, 18733909260242195, 144354928765952131, 1116015033661158079, 8654019249571514621, 67292250859412467583, 524583875375437922949

Offset

0,4

Comments

Suggested by Peter Doyle in an email message, Sep 04 2012

Links

N. J. A. Sloane, Table of n, a(n) for n = 0..100

Formula

INVERTi transform of A182216.

Crossrefs

Cf. A003319, A182216, A216040, A215252.

Sequence in context: A064062 A114191 A107592 * A367919 A350855 A295226

Adjacent sequences: A215254 A215255 A215256 * A215258 A215259 A215260

Keyword

nonn

Author

N. J. A. Sloane, Sep 07 2012. a(0)=0 added by N. J. A. Sloane, Sep 12 2012

Extensions

Name clarified by Peter Doyle, Dec 13 2013

Status

approved