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%I #18 Feb 20 2024 16:22:49
%S 1,3,5,8,13,21,32,47,71,108,163,245,368,555,837,1260,1897,2857,4304,
%T 6483,9763,14704,22147,33357,50240,75667,113965,171648,258525,389373,
%U 586448,883271,1330327,2003652,3017771,4545173,6845648,10310475,15528973,23388740,35226617,53056065,79909632,120354747,181270579,273018088
%N Coordination sequence for (2,6,6) tiling of hyperbolic plane.
%H G. C. Greubel, <a href="/A265069/b265069.txt">Table of n, a(n) for n = 0..1000</a>
%H J. W. Cannon, P. Wagreich, <a href="http://dx.doi.org/10.1007/BF01444714">Growth functions of surface groups</a>, Mathematische Annalen, 1992, Volume 293, pp. 239-257. See Prop. 3.1.
%H <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (1, 0, 1, 0, 1, -1).
%F G.f.: (x^5+x^4+x^3+x^2+x+1)*(x+1)/(x^6-x^5-x^3-x+1).
%t CoefficientList[Series[(x^5 + x^4 + x^3 + x^2 + x + 1) (x + 1)/(x^6 - x^5 - x^3 - x + 1), {x, 0, 60}], x] (* _Vincenzo Librandi_, Dec 30 2015 *)
%o (PARI) Vec((x^5+x^4+x^3+x^2+x+1)*(x+1)/(x^6-x^5-x^3-x+1) + O(x^50)) \\ _Michel Marcus_, Dec 30 2015
%Y Coordination sequences for triangular tilings of hyperbolic space: A001630, A007283, A054886, A078042, A096231, A163876, A179070, A265057, A265058, A265059, A265060, A265061, A265062, A265063, A265064, A265065, A265066, A265067, A265068, A265069, A265070, A265071, A265072, A265073, A265074, A265075, A265076, A265077.
%K nonn,easy
%O 0,2
%A _N. J. A. Sloane_, Dec 29 2015
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