%I #28 Aug 09 2024 10:32:42
%S 1,4,8,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
%T 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
%U 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6
%N Spherical growth series for Z as generated by {2, 3}.
%C Decimal expansion of 223/1500. - _Elmo R. Oliveira_, May 05 2024
%D P. de la Harpe, Topics in Geometric Group Theory, Univ. Chicago Press, 2000, p. 152.
%D Avinoam Mann, How Groups Grow, London Mathematical Society Lecture Note Series, Vol. 335, Cambridge University Press, 2012; ISBN: 1107657504,9781107657502. See Example 6, page 3.
%D P. Wagreich, The growth function of a discrete group (Lecture Notes in Mathematics, Vol. 956, Group Actions and Vector Fields, 1982, Vol. 956, pp. 125-144). Springer Berlin Heidelberg. See Example (3.2).
%H <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (1).
%F G.f.: (1+3*x+4*x^2-2*x^3)/(1-x).
%F a(n) = 6 for n >= 3. - _Elmo R. Oliveira_, May 05 2024
%F E.g.f.: 6*exp(x) - 5 - 2*x + x^2. - _Elmo R. Oliveira_, Aug 09 2024
%t PadRight[{1,4,8},100,6] (* _Paolo Xausa_, Nov 14 2023 *)
%Y Cf. A308196 (partial sums).
%K nonn,easy
%O 0,2
%A _N. J. A. Sloane_, Aug 20 2001