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 A159720 #6 May 14 2020 16:17:43
%S A159720 0,0,0,0,0,40272,62954948,24342647424,5320007368884,848044852469680,
%T A159720 111078667024032048,12769013592631944576,1340902091662029846456,
%U A159720 132008300342568131914656,12398363733385845967412220,1124539850663707285433353472,99357839137277548804214431980
%N A159720 Number of permutations of 2 indistinguishable copies of 1..n arranged in a circle with exactly 6 local maxima.
%H A159720 Andrew Howroyd, <a href="/A159720/b159720.txt">Table of n, a(n) for n = 1..200</a>
%o A159720 (PARI) \\ CircPeaksBySig defined in A334778.
%o A159720 a(n) = {CircPeaksBySig(vector(n, i, 2), [6])[1]} \\ _Andrew Howroyd_, May 13 2020
%Y A159720 Column 6 of A334778.
%Y A159720 Cf. A159716.
%K A159720 nonn
%O A159720 1,6
%A A159720 _R. H. Hardin_, Apr 20 2009
%E A159720 Terms a(10) and beyond from _Andrew Howroyd_, May 13 2020