login
A Chebyshev transform of A006053 related to the knot 7_1.
1

%I #6 Apr 17 2024 15:18:55

%S 0,1,1,1,1,0,0,0,-1,-1,-1,-1,0,0,0,1,1,1,1,0,0,0,-1,-1,-1,-1,0,0,0,1,

%T 1,1,1,0,0,0,-1,-1,-1,-1,0,0,0,1,1,1,1,0,0,0,-1,-1,-1,-1,0,0,0,1,1,1,

%U 1,0,0,0,-1,-1,-1,-1,0,0,0,1,1,1,1,0,0,0,-1,-1,-1,-1

%N A Chebyshev transform of A006053 related to the knot 7_1.

%C The g.f. is the transform of the g.f. of A006053 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.

%F G.f.: x(1+x^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)}.

%Y Cf. A099860.

%K easy,sign

%O 0,1

%A _Paul Barry_, Oct 28 2004