A113888 a(n) = C(2*n+1,n)*C(2*n+6,n+1).

6, 84, 1200, 17325, 252252, 3699696, 54609984, 810616950, 12092280200, 181176906768, 2725140250560, 41132585656890, 622787147955000, 9456196695480000, 143946539451475200, 2196309308974461450, 33581927605139911800, 514470608092210770000, 7895695609776494520000

Offset: 0

Author

Zerinvary Lajos, Jan 28 2006

Keywords

• easy
• nonn
• changed

Examples

			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.
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.
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.
		

Crossrefs

Cf. A001700, A002694, A062190.

Programs

Mathematica

Table[Binomial[2n+1,n]Binomial[2n+6,n+1],{n,0,20}] (* Harvey P. Dale, Jun 14 2011 *)

Formula

From Amiram Eldar, Sep 06 2025: (Start)

a(n) = A001700(n) * A002694(n+3).

a(n) ~ 2^(4*n+7) / (Pi*n). (End)

Extensions

Edited by N. J. A. Sloane, Feb 03 2007