OFFSET
0,2
COMMENTS
The diagram is o---o-(5)-o---o.
LINKS
Colin Barker, Table of n, a(n) for n = 0..1000
Maxim Chapovalov, Dimitry Leites, and Rafael Stekolshchik, The Poincaré series of the hyperbolic Coxeter groups with finite volume of fundamental domains, arXiv:0906.1596 [math.RT], 2009.
Maxim Chapovalov, Dimitry Leites, and Rafael Stekolshchik, The Poincaré series of the hyperbolic Coxeter groups with finite volume of fundamental domains, Journal of Nonlinear Mathematical Physics 17.supp01 (2010): 169-215.
R. L. Worthington, The growth series of compact hyperbolic Coxeter groups, with 4 and 5 generators, Canad. Math. Bull. 41(2) (1998) 231-239.
Index entries for linear recurrences with constant coefficients, signature (2,-1,0,1,-2,2,-1,0,1,-2,1).
FORMULA
G.f.: -b(2)*b(3)*(1+x^3)*(1+x^5)/((x-1)*(x^10-x^9-x^6+x^5-x^4-x+1)) where b(k) = (1-x^k)/(1-x).
G.f.: (1+x)^3*(1-x+x^2)*(1+x+x^2)*(1-x+x^2-x^3+x^4) / ((1-x)*(1-x-x^4+x^5-x^6-x^9+x^10)). - Colin Barker, Jan 01 2016
PROG
(PARI) Vec((1+x)^3*(1-x+x^2)*(1+x+x^2)*(1-x+x^2-x^3+x^4)/((1-x)*(1-x-x^4+x^5-x^6-x^9+x^10)) + O(x^50)) \\ Colin Barker, Jan 01 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Dec 27 2015
STATUS
approved