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 A152498 #6 May 12 2020 12:55:00
%S A152498 0,0,0,0,0,76739,42734373,10478384089,1717626773713,222419564005134,
%T A152498 24781841211038024,2496351029911357950,234485896532293552830,
%U A152498 20959967704130971672341,1807748255927878129526087,151901517836714997413430591,12521620421275657891377640951
%N A152498 1/3 of the number of permutations of 2 indistinguishable copies of 1..n with exactly 6 local maxima.
%H A152498 Andrew Howroyd, <a href="/A152498/b152498.txt">Table of n, a(n) for n = 1..200</a>
%F A152498 a(n) = A334774(n,5)/3. - _Andrew Howroyd_, May 12 2020
%o A152498 (PARI) \\ PeaksBySig defined in A334774.
%o A152498 a(n)={PeaksBySig(vector(n,i,2), [5])[1]/3}
%Y A152498 Cf. A334774.
%K A152498 nonn
%O A152498 1,6
%A A152498 _R. H. Hardin_, Dec 06 2008
%E A152498 Terms a(11) and beyond from _Andrew Howroyd_, May 12 2020