A004824 Denominator of 2^n*(3*n-3)!/( ((n-1)!)^3 * (2*n)! ).

1, 1, 1, 3, 36, 900, 675, 66150, 6350400, 34292160, 857304000, 12966723000, 222286680000, 2366686281960000, 57983813908020000, 1581376742946000000, 2226578454067968000000, 55155529133626521600000, 114553791277532006400000, 3490915210814660428800000

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• frac

Links

• Pavel Valtr, The probability that n random points in a triangle are in convex position, Combinatorica 16 (1996), no. 4, 567-573.
• Eric Weisstein's World of Mathematics, Sylvester's Four-Point Theorem.

Crossrefs

Numerators are in A004677.

Extensions

Typo in title corrected by Sean A. Irvine, Feb 08 2016