%I #7 Mar 31 2012 13:21:38

%S 1,2,6,20,69,246,896,3312,12371,46582,176528,672464,2572700,9878116,

%T 38044450,146911680,568617615,2205268306,8567986878,33341710740,

%U 129932332749,506997589626,1980621229040,7745660095820,30320567651424

%N T(n,n+1), array T as in A047030.

%C If Y is a fixed 4-subset of a 2n-set X then a(n) is the number of n-subsets of X intersecting Y - _Milan Janjic_, Oct 21 2007

%H Milan Janjic, <a href="http://www.pmfbl.org/janjic/">Two Enumerative Functions</a>

%K nonn

%O 0,2

%A _Clark Kimberling_