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 A009045 #19 Sep 08 2022 08:44:37
%S A009045 1,-1,0,2,0,-16,24,104,-256,-1600,5632,29952,-156032,-644736,4761600,
%T A009045 18383616,-178225152,-645554176,8081772544,25645936640,-422364381184,
%U A009045 -1160636121088,25184814366720,60217271582720,-1713906141986816
%N A009045 Expansion of cos(sin(x))/exp(x).
%H A009045 G. C. Greubel, <a href="/A009045/b009045.txt">Table of n, a(n) for n = 0..250</a>
%t A009045 With[{nn=30},CoefficientList[Series[Cos[Sin[x]]/Exp[x],{x,0,nn}],x]Range[0,nn]!] (* _Harvey P. Dale_, Dec 31 2012 *)
%o A009045 (PARI) x='x+O('x^30); Vec(serlaplace(cos(sin(x))/exp(x))) \\ _G. C. Greubel_, Jul 23 2018
%o A009045 (Magma) m:=30; R<x>:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!(Cos(Sin(x))/Exp(x))); [Factorial(n-1)*b[n]: n in [1..m]]; // _G. C. Greubel_, Jul 23 2018
%K A009045 sign,easy
%O A009045 0,4
%A A009045 _R. H. Hardin_
%E A009045 Extended with signs by _Olivier Gérard_, Mar 15 1997