A113888 - OEIS

%I #15 Sep 30 2023 16:40:15

%S 6,84,1200,17325,252252,3699696,54609984,810616950,12092280200,

%T 181176906768,2725140250560,41132585656890,622787147955000,

%U 9456196695480000,143946539451475200,2196309308974461450,33581927605139911800,514470608092210770000,7895695609776494520000

%N a(n) = C(2*n+1,n)*C(2*n+6,n+1).

%e If n=0 then C(1+2*0,0+0)*C(6+2*0,1+0) = C(1,0)*C(6,1) = 1*6 = 6.

%e If n=4 then C(1+2*4,0+4)*C(6+2*4,1+4) = C(9,4)*C(14,5) = 126*2002 = 252252.

%e If n=10 then C(1+2*10,0+10)*C(6+2*10,1+10) = C(21,10)*C(26,11) = 352716*7726160 = 2725140250560.

%t Table[Binomial[2n+1,n]Binomial[2n+6,n+1],{n,0,20}] (* _Harvey P. Dale_, Jun 14 2011 *)

%Y Cf. A062190.

%K easy,nonn

%O 0,1

%A _Zerinvary Lajos_, Jan 28 2006

%E Edited by _N. J. A. Sloane_, Feb 03 2007