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 A153191 #30 Jan 03 2024 08:46:28
%S A153191 0,1,9,87,837,8055,77517,745983,7178949,69086439,664851645,6398183439,
%T A153191 61572760821,592543948023,5702332097133,54876252562335,
%U A153191 528100265643813,5082159906168327,48908040749377821,470665326181410351
%N A153191 a(n) = 9*a(n-1) + 6*a(n-2); a(0)=0, a(1)=1.
%H A153191 G. C. Greubel, <a href="/A153191/b153191.txt">Table of n, a(n) for n = 0..1000</a>
%H A153191 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (9, 6).
%F A153191 G.f.: x/(1 - 9*x - 6*x^2).
%p A153191 a[0]:=0:a[1]:=1:for n from 2 to 50 do a[n]:=9*a[n-1]+6*a[n-2]od: seq(a[n], n=0..33);
%t A153191 LinearRecurrence[{9,6}, {0,1}, 25] (* _G. C. Greubel_, Jan 24 2018 *)
%o A153191 (Sage) [lucas_number1(n,9,-6) for n in range(0, 25)]# _Zerinvary Lajos_, Apr 26 2009
%o A153191 (PARI) x='x+O('x^25); concat([0], Vec(x/(1-9*x-6*x^2))) \\ _G. C. Greubel_, Jan 24 2018
%o A153191 (Magma) I:=[0,1]; [n le 2 select I[n] else 9*Self(n-1) + 6*Self(n-2): n in [1..25]]; // _G. C. Greubel_, Jan 24 2018
%Y A153191 Cf. A015579, A099371.
%K A153191 nonn
%O A153191 0,3
%A A153191 _Zerinvary Lajos_, Dec 20 2008
%E A153191 Formula corrected by _Philippe Deléham_, Dec 20 2008
%E A153191 Edited by _N. J. A. Sloane_, Dec 21 2008