%I #6 Jun 13 2019 17:28:38

%S 1,36,1260,44100,1543500,54022500,1890787500,66177562500,

%T 2316214687500,81067514062500,2837362992187500,99307704726562500,

%U 3475769665429687500,121651938290039062500,4257817840151367187500,149023624405297851562500

%N Growth series for fundamental group of orientable closed surface of genus 9.

%D P. de la Harpe, Topics in Geometric Group Theory, Univ. Chicago Press, 2000, p. 160, Sigma(Gamma_9, S_9; z).

%H Colin Barker, <a href="/A063819/b063819.txt">Table of n, a(n) for n = 0..600</a>

%H <a href="/index/Rec#order_19">Index entries for linear recurrences with constant coefficients</a>, signature (35,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-35,1).

%F G.f.: (1+x)*(1-x^18)/(1-35*x+35*x^18-x^19).

%o (PARI) Vec((1+x)*(1-x^18)/(1-35*x+35*x^18-x^19) + O(x^15)) \\ _Colin Barker_, Jun 13 2019

%K nonn,easy

%O 0,2

%A _N. J. A. Sloane_, Aug 21 2001