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 A099452 #12 Apr 18 2019 09:57:14 %S A099452 1,5,16,40,79,110,23,-520,-2336,-6995,-16574,-31075,-38848,9560, %T A099452 258631,1043950,2978719,6781640,12060848,13119125,-12022526, %U A099452 -124662155,-461573264,-1259138680,-2752822273,-4615067410,-4134056729,8360350360,58685747584,202130368445,528415922498 %N A099452 An Alexander sequence for the knot 7_7. %C A099452 The denominator is a parameterization of the Alexander polynomial for the knot 7_7. 1/(1-5*x+9*x^2-5*x^3+x^4) is the image of the g.f. of A099450 under the modified Chebyshev transform A(x)->(1/(1+x^2)^2)A(x/(1+x^2)). %H A099452 Dror Bar-Natan, <a href="http://katlas.org/wiki/Main_Page">The Rolfsen Knot Table</a> %H A099452 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (5,-9,5,-1). %F A099452 G.f.: (1-x)*(1+x)*(1+x^2)/(1-5*x+9*x^2-5*x^3+x^4). - corrected by _R. J. Mathar_, Nov 24 2012 %F A099452 a(n)=A099451(n)-A099451(n-2). %t A099452 LinearRecurrence[{5,-9,5,-1},{1,5,16,40,79},40] (* _Harvey P. Dale_, Apr 18 2019 *) %K A099452 easy,sign %O A099452 0,2 %A A099452 _Paul Barry_, Oct 16 2004