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%I #12 Apr 18 2019 09:57:14
%S 1,5,16,40,79,110,23,-520,-2336,-6995,-16574,-31075,-38848,9560,
%T 258631,1043950,2978719,6781640,12060848,13119125,-12022526,
%U -124662155,-461573264,-1259138680,-2752822273,-4615067410,-4134056729,8360350360,58685747584,202130368445,528415922498
%N An Alexander sequence for the knot 7_7.
%C 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 Dror Bar-Natan, <a href="http://katlas.org/wiki/Main_Page">The Rolfsen Knot Table</a>
%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (5,-9,5,-1).
%F 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 a(n)=A099451(n)-A099451(n-2).
%t LinearRecurrence[{5,-9,5,-1},{1,5,16,40,79},40] (* _Harvey P. Dale_, Apr 18 2019 *)
%K easy,sign
%O 0,2
%A _Paul Barry_, Oct 16 2004