A051790 - OEIS

%I #10 Feb 18 2019 10:50:35

%S 0,0,0,10,364,11480,374660,13067054,486345860,19143687420,

%T 789566607180,33856987804640,1500056631216220,68334193148209300,

%U 3188209413930298680,151869731557849844790,7367151946247774981940,363173327612427801849380

%N a(n) = C(n)*(C(n)-1)*(C(n)-2)/6, where C(n) are the Catalan numbers (A000108).

%F a(n) = binomial(binomial(2*n, n)/(n+1), 3). - _Zerinvary Lajos_, May 29 2006

%p [seq (binomial(binomial(2*n,n)/(n+1),3), n=0..24)]; # _Zerinvary Lajos_, May 29 2006

%t (#(#-1)(#-2))/6&/@CatalanNumber[Range[0,20]] (* _Harvey P. Dale_, Oct 12 2014 *)

%Y Cf. A000108.

%K nonn

%O 0,4

%A _N. J. A. Sloane_, Dec 10 1999