A134357 Denominator of binomial(6*n-2,2*n)/(2*binomial(4*n-1,2*n)).

2, 1, 1, 3, 13, 34, 133, 115, 435, 59334, 2294, 19721, 195693, 4060189, 12746447, 331303, 25369351, 4959422, 11092118, 28745223797, 16310849170, 14814154260, 348379527681, 263145320733, 1493627665569, 100023828627, 531705615333, 156537259557, 1047443521637

Offset: 0

Author

N. J. A. Sloane, May 04 2008

Keywords

• nonn
• frac

Comments

It is conjectured that binomial(6*n-2,2*n)/(2*binomial(4*n-1,2*n)) = A005156(n+1)/A005156(n).

Examples

			1/2, 1, 3, 26/3, 323/13, 2415/34, 26970/133, 66526/115, 717541/435, 278992987/59334, 30741431/2294, ...
		

References

• D. M. Bressoud, Proofs and Confirmations, Camb. Univ. Press, 1999; see conjecture (6.18).

Links

• Harvey P. Dale, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A109074, A005156.

Programs

Mathematica

Table[Binomial[6n-2,2n]/(2Binomial[4n-1,2n]),{n,0,30}]//Denominator (* Harvey P. Dale, Feb 05 2025 *)

Extensions

Changed numerator to denominator in title, Arvind Ayyer, Jan 29 2012