This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A004824 #23 Feb 16 2025 08:32:28 %S A004824 1,1,1,3,36,900,675,66150,6350400,34292160,857304000,12966723000, %T A004824 222286680000,2366686281960000,57983813908020000,1581376742946000000, %U A004824 2226578454067968000000,55155529133626521600000,114553791277532006400000,3490915210814660428800000 %N A004824 Denominator of 2^n*(3*n-3)!/( ((n-1)!)^3 * (2*n)! ). %H A004824 Pavel Valtr, <a href="https://doi.org/10.1007/BF01271274">The probability that n random points in a triangle are in convex position</a>, Combinatorica 16 (1996), no. 4, 567-573. %H A004824 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SylvestersFour-PointProblem.html">Sylvester's Four-Point Theorem</a>. %Y A004824 Numerators are in A004677. %K A004824 nonn,frac %O A004824 1,4 %A A004824 _N. J. A. Sloane_ %E A004824 Typo in title corrected by _Sean A. Irvine_, Feb 08 2016