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 A151576 #9 May 07 2020 11:59:07
%S A151576 0,4,55,396,2114,9528,38637,146080,526240,1831644,6217523,20716164,
%T A151576 68059710,221195824,712856665,2282058360,7266358556,23035517940,
%U A151576 72760054815,229112753980,719545590010,2254604460264,7050252659525,22006821057936,68581455012504,213411502891468
%N A151576 Number of permutations of 1..n arranged in a circle with exactly 3 adjacent element pairs in decreasing order.
%C A151576 Exactly 2 adjacent element pairs in decreasing order gives A027540(n-1).
%H A151576 Andrew Howroyd, <a href="/A151576/b151576.txt">Table of n, a(n) for n = 3..500</a>
%H A151576 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (16,-111,438,-1083,1740,-1817,1190,-444,72).
%F A151576 From _Andrew Howroyd_, May 05 2020: (Start)
%F A151576 a(n) = n*A000460(n-1).
%F A151576 a(n) = n*(3^(n-1) - n*2^(n-1) + n*(n-1)/2).
%F A151576 a(n) = 16*a(n-1) - 111*a(n-2) + 438*a(n-3) - 1083*a(n-4) + 1740*a(n-5) - 1817*a(n-6) + 1190*a(n-7) - 444*a(n-8) + 72*a(n-9).
%F A151576 G.f.: x^4*(4 - 9*x - 40*x^2 + 131*x^3 - 98*x^4)/((1 - x)^4*(1 - 2*x)^3*(1 - 3*x)^2).
%F A151576 (End)
%o A151576 (PARI) a(n)={n*(3^(n-1) - n*2^(n-1) + n*(n-1)/2)} \\ _Andrew Howroyd_, May 05 2020
%Y A151576 Column k=3 of A334218.
%Y A151576 Related sequences: A151577-A151610.
%Y A151576 Cf. A000460.
%K A151576 nonn,easy
%O A151576 3,2
%A A151576 _R. H. Hardin_, May 21 2009
%E A151576 Terms a(18) and beyond from _Andrew Howroyd_, May 05 2020