A114059 a(n) = binomial(3+2*n, n) * binomial(8+2*n, 3+n).

56, 1050, 16632, 252252, 3775200, 56316546, 840639800, 12575971408, 188663555808, 2838687761000, 42836302222560, 648207031545000, 9834444563299200, 149569451148798450, 2279905857066915000, 34825702701626575200, 532997250488883180000, 8172044956118671828200

Offset: 0

Author

Zerinvary Lajos, Feb 02 2006

Keywords

• easy
• nonn
• changed

Examples

			a(0) = C(3+2*0,0)*C(8+2*0,3+0) = C(3,0)*C(8,3) = 1*56 = 56.
a(10) = C(3+2*10,10)*C(8+2*10,3+10) = C(23,10)*C(28,13) = 1144066*37442160 = 42836302222560.
		

Links

• Andrew Howroyd, Table of n, a(n) for n = 0..200

Crossrefs

Cf. A062190.

Programs

Mathematica

a[n_] := Binomial[3+2*n, n] * Binomial[8+2*n, 3+n]; Array[a, 20, 0] (* Amiram Eldar, Sep 05 2025 *)

PARI

a(n)={binomial(3+2*n, n) * binomial(8+2*n, 3+n)} \\ Andrew Howroyd, Jan 07 2020

Formula

a(n) = A062190(3+2*n, 3+n).

a(n) ~ 2^(4*n+11) / (Pi*n). - Amiram Eldar, Sep 05 2025

Extensions

Name edited and terms a(11) and beyond from Andrew Howroyd, Jan 07 2020