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 A099860 #11 Apr 17 2024 15:19:23
%S A099860 1,1,2,2,1,1,0,-1,-1,-2,-2,-1,-1,0,1,1,2,2,1,1,0,-1,-1,-2,-2,-1,-1,0,
%T A099860 1,1,2,2,1,1,0,-1,-1,-2,-2,-1,-1,0,1,1,2,2,1,1,0,-1,-1,-2,-2,-1,-1,0,
%U A099860 1,1,2,2,1,1,0,-1,-1,-2,-2,-1,-1,0,1,1,2,2,1,1,0,-1,-1,-2,-2
%N A099860 A Chebyshev transform related to the knot 7_1.
%C A099860 The g.f. is the transform of the g.f. of A006053(n+1) under the Chebyshev mapping G(x)-> (1/(1+x^2))G(x/(1+x^2)). The denominator of the g.f. is a parameterization of the Alexander polynomial of 7_1. It is also the 14th cyclotomic polynomial.
%H A099860 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (1,-1,1,-1,1,-1).
%F A099860 G.f.: (1+x^2)^2/(1-x+x^2-x^3+x^4-x^5+x^6); a(n)=sum{k=0..floor(n/2), binomial(n-k, k)(-1)^k*A006053(n-2k+1)}.
%t A099860 LinearRecurrence[{1,-1,1,-1,1,-1},{1,1,2,2,1,1},100] (* _Harvey P. Dale_, May 21 2019 *)
%Y A099860 Cf. A099859.
%K A099860 easy,sign
%O A099860 0,3
%A A099860 _Paul Barry_, Oct 28 2004