OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Horton, Matthew D., H. M. Stark, and Audrey A. Terras. What are zeta functions of graphs and what are they good for? Contemporary Mathematics 415 (2006): 173-190. The graph is shown on the left in Fig. 1.
Index entries for linear recurrences with constant coefficients, signature (3, 3, -6, -9, -15, 35, 60, -75, -75, 81, 42, -43, -9, 9).
FORMULA
G.f.: 1/(-(1-x)^6*(x+1)^5*(9*x^3+2*x-1)). - Vincenzo Librandi, Apr 16 2014
a(n) = 3*a(n-1) + 3*a(n-2) - 6*a(n-3) - 9*a(n-4) - 15*a(n-5) + 35*a(n-6) + 60*a(n-7) - 75*a(n-8) - 75*a(n-9) + 81*a(n-10) + 42*a(n-11) - 43*a(n-12) - 9*a(n-13) + 9*a(n-14) for n > 13. - Chai Wah Wu, Jan 19 2020
EXAMPLE
The zeta function is 1/((1-x^10)^5*(1-3*x^5)*(1-x^5)*(1+x^5+3*x^10)).
MATHEMATICA
CoefficientList[Series[1/(-(1 - x)^6 (x + 1)^5 (9 x^3 + 2 x - 1)), {x, 0, 50}], x] (* Vincenzo Librandi, Apr 16 2014 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Apr 15 2014
STATUS
approved