A combinatorial interpretation of the numbers $6(2n)!/n!(n+2)!$
J. Integer Seq. 8(2), Art. 05.2.3, 13 p., electronic only (2005)
Summary
Summary: It is well known that the numbers $(2m)!(2n)!/m!n!(m+n)$! are integers, but in general there is no known combinatorial interpretation for them. When $m=0$ these numbers are the middle binomial coefficients $C(2n,n)$, and when $m=1$ they are twice the Catalan numbers. In this paper, we give combinatorial interpretations for these numbers when $m=2$ or 3.
Mathematics Subject Classification
05A10, 05A15
Keywords/Phrases
Dyck paths, super Catalan numbers (Concerned with sequences and
