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 A159717 #8 May 13 2020 13:00:35
%S A159717 0,0,6,1192,61830,2150688,62178928,1629254640,40346856234,
%T A159717 965510596600,22606163844396,521603874280248,11911230805813846,
%U A159717 269907065756299440,6079103449024019880,136243494317831152480,3040751938796332410018,67621304208554979697224,1499043510801269678080708
%N A159717 Number of permutations of 2 indistinguishable copies of 1..n arranged in a circle with exactly 3 local maxima.
%H A159717 Andrew Howroyd, <a href="/A159717/b159717.txt">Table of n, a(n) for n = 1..200</a>
%o A159717 (PARI) \\ CircPeaksBySig defined in A334778.
%o A159717 a(n) = {CircPeaksBySig(vector(n, i, 2), [3])[1]} \\ _Andrew Howroyd_, May 13 2020
%Y A159717 Column 3 of A334778.
%Y A159717 Cf. A159716.
%K A159717 nonn
%O A159717 1,3
%A A159717 _R. H. Hardin_, Apr 20 2009
%E A159717 Terms a(11) and beyond from _Andrew Howroyd_, May 13 2020