A combinatorial interpretation of the numbers 6(2n)!/n!(n+2)!.
Gessel, Ira M. ; Xin, Guoce
Journal of Integer Sequences [electronic only], Tome 8 (2005), / Harvested from The Electronic Library of Mathematics
Access to full text
Full (PDF)
Publié le : 2005-01-01
EUDML-ID : urn:eudml:doc:51326 
@article{02186902,
     title = {A combinatorial interpretation of the numbers },
     journal = {Journal of Integer Sequences [electronic only]},
     volume = {8},
     year = {2005},
     zbl = {1064.05006},
     language = {en},
     url = {http://dml.mathdoc.fr/item/02186902}
}

Gessel, Ira M.; Xin, Guoce. A combinatorial interpretation of the numbers . Journal of Integer Sequences [electronic only], Tome 8 (2005) . http://gdmltest.u-ga.fr/item/02186902/