A055219 - OEIS

%I #7 Mar 30 2012 18:57:04

%S 1,5,21,78,274,927,3061,9933,31824,100972,317942,995088,3099105,

%T 9612735,29715525,91595391,281643480,864189486,2646805668,8093543439,

%U 24713953515,75370741506,229604257846,698754428388,2124616182139

%N T(2n+3,n), array T as in A055216.

%F Apparently a(n)=sum((-1)^j*binomial(n+3, j)*binomial(2n+3-3j, n+3), j=0..floor(n/3)). - _Emeric Deutsch_, Mar 13 2004

%K nonn

%O 0,2

%A _Clark Kimberling_, May 07 2000