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 A303867 #10 Jun 01 2022 06:13:02 %S A303867 1,2,21,494,18086,794696,38695548,2015556488,110292751866, %T A303867 6267709291736,367003473639464,22018423100856184,1347856204419978236, %U A303867 83918845269760695536,5300972002005297517812,339058084617031980524000,21924124400037221008705338,1431303944222490626674244672 %N A303867 Number of noncrossing path sets on 4*n nodes up to rotation and reflection with each path having exactly 4 nodes. %H A303867 Andrew Howroyd, <a href="/A303867/b303867.txt">Table of n, a(n) for n = 0..200</a> %H A303867 Math StackExchange, <a href="https://math.stackexchange.com/questions/1294224/">Question from user Matan at math.stackexchange.com: Number of ways to connect sets of k dots in a perfect n-gon</a> %F A303867 a(n) ~ 2^(11*n - 5/2) / (sqrt(Pi) * n^(5/2) * 3^(3*n + 3/2)). - _Vaclav Kotesovec_, Jun 01 2022 %Y A303867 Column 4 of A302828. %Y A303867 Cf. A303330, A303839, A303866. %K A303867 nonn %O A303867 0,2 %A A303867 _Andrew Howroyd_, May 01 2018