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 A152505 #9 Jul 19 2020 08:23:48
%S A152505 0,3,1008,172573,24118698,3148308323,401420959948,50776368194073,
%T A152505 6405835208453198,807454401764399823,101751780468757346448,
%U A152505 12821210170324927605573,1615491145485759589239698,203552595669637872843811323,25647653984634161426074132948
%N A152505 1/10 of the number of permutations of 4 indistinguishable copies of 1..n with exactly 3 local maxima.
%H A152505 Andrew Howroyd, <a href="/A152505/b152505.txt">Table of n, a(n) for n = 1..200</a>
%H A152505 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (211,-13060,319850,-3093125,12831875,-19293750).
%F A152505 From _Colin Barker_, Jul 19 2020: (Start)
%F A152505 G.f.: x^2*(3 + 375*x - 935*x^2 - 89275*x^3 - 63000*x^4) / ((1 - 5*x)^3*(1 - 35*x)^2*(1 - 126*x)).
%F A152505 a(n) = 211*a(n-1) - 13060*a(n-2) + 319850*a(n-3) - 3093125*a(n-4) + 12831875*a(n-5) - 19293750*a(n-6) for n>6.
%F A152505 (End)
%o A152505 (PARI) \\ PeaksBySig defined in A334774.
%o A152505 a(n) = {PeaksBySig(vector(n,i,4), [2])[1]/10} \\ _Andrew Howroyd_, May 12 2020
%o A152505 (PARI) concat(0, Vec(x^2*(3 + 375*x - 935*x^2 - 89275*x^3 - 63000*x^4) / ((1 - 5*x)^3*(1 - 35*x)^2*(1 - 126*x)) + O(x^15))) \\ _Colin Barker_, Jul 19 2020
%Y A152505 Cf. A152504, A334774.
%K A152505 nonn,easy
%O A152505 1,2
%A A152505 _R. H. Hardin_, Dec 06 2008
%E A152505 Terms a(8) and beyond from _Andrew Howroyd_, May 12 2020