OFFSET
0,2
COMMENTS
The denominator is a parameterization of the Alexander polynomial for the knot 8_12. 1/(1-7*x+13*x^2-7*x^3+x^4) is the image of the g.f. of A099453 under the modified Chebyshev transform A(x)->(1/(1+x^2)^2)A(x/(1+x^2)).
LINKS
Stefano Spezia, Table of n, a(n) for n = 0..1500
Dror Bar-Natan, The Rolfsen Knot Table.
Index entries for linear recurrences with constant coefficients, signature (7,-13,7,-1).
FORMULA
MATHEMATICA
LinearRecurrence[{7, -13, 7, -1}, {1, 7, 36, 168, 755}, 30] (* Harvey P. Dale, Jan 31 2017 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Oct 16 2004
STATUS
approved