A217213 2*A002740(n).

0, 0, 0, 4, 30, 168, 840, 3960, 18018, 80080, 350064, 1511640, 6466460, 27457584, 115892400, 486748080, 2035917450, 8485840800, 35263382880, 146157442200, 604404010980, 2494365759600, 10275832148400, 42264944401680, 173588164506900, 712027089322848, 2917167840871200, 11938779496898800

Offset

0,4

Links

Table of n, a(n) for n=0..27.

Luca Ferrari and Emanuele Munarini, Enumeration of saturated chains in Dyck lattices, arXiv preprint arXiv:1203.6807, 2012

Crossrefs

Cf. A002740.

Sequence in context: A123351 A305525 A316999 * A119697 A316817 A317567

Adjacent sequences: A217210 A217211 A217212 * A217214 A217215 A217216

Keyword

nonn

Author

N. J. A. Sloane, Oct 03 2012

Status

approved