@article{JIS_2005__8_2_a2, author = {Gessel, Ira M. and Xin, Guoce}, title = {A combinatorial interpretation of the numbers \(6(2n)!/n!(n+2)!\)}, journal = {Journal of integer sequences}, year = {2005}, volume = {8}, number = {2}, zbl = {1064.05006}, language = {en}, url = {http://geodesic.mathdoc.fr/item/JIS_2005__8_2_a2/} }