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 A159728 #14 Aug 12 2020 12:09:12
%S A159728 36,2610,129800,5748750,241987500,9885006250,395426250000,
%T A159728 15570077343750,605504070312500,23311913238281250,890091272109375000,
%U A159728 33749294301074218750,1272088786561523437500,47703329503967285156250,1780924301526757812500000,66228122463283630371093750
%N A159728 Number of permutations of 4 indistinguishable copies of 1..n arranged in a circle with exactly 2 local maxima.
%H A159728 Andrew Howroyd, <a href="/A159728/b159728.txt">Table of n, a(n) for n = 2..200</a>
%H A159728 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (85,-2350,23750,-100625,153125).
%F A159728 a(n) = 2*n*(121*35^(n-2) + 8*5^(n-2) - 24*n*5^(n-2))/9. - _Andrew Howroyd_, May 10 2020
%o A159728 (PARI) a(n) = {2*n*(121*35^(n-2) + 8*5^(n-2) - 24*n*5^(n-2))/9} \\ _Andrew Howroyd_, May 10 2020
%o A159728 (PARI) Vec(2*x^2*(3 + 5*x)*(6 - 85*x - 1100*x^2 + 875*x^3) / ((1 - 5*x)^3*(1 - 35*x)^2) + O(x^40)) \\ _Colin Barker_, Jul 16 2020
%Y A159728 Column k=4 of A334772.
%Y A159728 Cf. A159716.
%K A159728 nonn,easy
%O A159728 2,1
%A A159728 _R. H. Hardin_, Apr 20 2009
%E A159728 Terms a(8) and beyond from _Andrew Howroyd_, May 09 2020