This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A265068 #20 Feb 20 2024 16:21:58
%S A265068 1,3,5,8,13,20,30,46,71,109,167,256,393,603,925,1419,2177,3340,5124,
%T A265068 7861,12060,18502,28385,43547,66808,102494,157242,241234,370091,
%U A265068 567778,871061,1336345,2050164,3145275,4825348,7402845,11357132,17423632,26730600,41008957,62914209,96520321,148077398,227174087,348520885
%N A265068 Coordination sequence for (2,5,infinity) tiling of hyperbolic plane.
%H A265068 G. C. Greubel, <a href="/A265068/b265068.txt">Table of n, a(n) for n = 0..1000</a>
%H A265068 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 A265068 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (0, 1, 1, 1, 1).
%F A265068 G.f.: -(x^4+x^3+x^2+x+1)*(x+1)^2/(x^5+x^4+x^3+x^2-1).
%t A265068 CoefficientList[Series[-(x^4 + x^3 + x^2 + x + 1) (x + 1)^2/(x^5 + x^4 + x^3 + x^2 - 1), {x, 0, 60}], x] (* _Vincenzo Librandi_, Dec 30 2015 *)
%o A265068 (PARI) Vec(-(x^4+x^3+x^2+x+1)*(x+1)^2/(x^5+x^4+x^3+x^2-1) + O(x^50)) \\ _Michel Marcus_, Dec 30 2015
%Y A265068 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 A265068 nonn,easy
%O A265068 0,2
%A A265068 _N. J. A. Sloane_, Dec 29 2015