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 A292293 #15 Sep 18 2017 08:03:36
%S A292293 0,0,0,0,3,24,177,1347,10467,82029,644808,5073915,39939900,314427960,
%T A292293 2475438408,19488960504,153435934587,1207997701872,9510543548457,
%U A292293 74876345104299,589500202673403,4641125238026805,36539501601385200,287674887310843395,2264859596198883588
%N A292293 Number of vertices of type D at level n of the hyperbolic Pascal pyramid.
%H A292293 Colin Barker, <a href="/A292293/b292293.txt">Table of n, a(n) for n = 0..1000</a>
%H A292293 László Németh, <a href="http://arxiv.org/abs/1511.02067">Hyperbolic Pascal pyramid</a>, arXiv:1511.0267 [math.CO], 2015 (4th line of Table 1).
%H A292293 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (12,-37,37,-12,1).
%F A292293 a(n) = 12*a(n-1) - 37*a(n-2) + 37*a(n-3) - 12*a(n-4) + a(n-5), n >= 6.
%F A292293 G.f.: 3*x^4*(1 - 4*x) / ((1 - x)*(1 - 8*x + x^2)*(1 - 3*x + x^2)). - _Colin Barker_, Sep 17 2017
%t A292293 CoefficientList[Series[3*x^4*(1 - 4*x)/((1 - x)*(1 - 8*x + x^2)*(1 - 3*x + x^2)), {x, 0, 30}], x] (* _Wesley Ivan Hurt_, Sep 17 2017 *)
%o A292293 (PARI) concat(vector(4), Vec(3*x^4*(1 - 4*x) / ((1 - x)*(1 - 8*x + x^2)*(1 - 3*x + x^2)) + O(x^30))) \\ _Colin Barker_, Sep 17 2017
%Y A292293 Cf. A264236.
%K A292293 nonn,easy
%O A292293 0,5
%A A292293 _Eric M. Schmidt_, Sep 13 2017