%I #33 Mar 02 2021 16:31:29
%S 1,8,29,85,232,617,1625,4264,11173,29261,76616,200593,525169,1374920,
%T 3599597,9423877,24672040,64592249,169104713,442721896,1159060981,
%U 3034461053,7944322184,20798505505,54451194337,142555077512,373214038205,977087037109,2558047073128,6697054182281,17533115473721,45902292238888
%N Crystal ball sequence for hyperbolic tessellation 3^7 (from triangle group (2,3,7)).
%H Georg Fischer, <a href="/A001360/b001360.txt">Table of n, a(n) for n = 0..1000</a>
%H <a href="/index/Cor#crystal_ball">Index entries for crystal ball sequences</a>
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (4,-4,1).
%F a(n) = 4*a(n-1)-4*a(n-2)+a(n-3). G.f.: (1+4*x+x^2)/((1-x)*(1-3*x+x^2)): partial sums of A001354. - _Colin Barker_, Mar 16 2012
%t LinearRecurrence[{4,-4,1}, {1,8,29}, 32] (* _Georg Fischer_, Mar 02 2021 *)
%Y Cf. A001354.
%K nonn,easy,nice
%O 0,2
%A _N. J. A. Sloane_.
%E More terms from _Georg Fischer_, Mar 02 2021