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 A015575 #36 Dec 18 2023 10:03:42
%S A015575 0,1,8,69,592,5081,43608,374269,3212192,27568881,236612008,2030740469,
%T A015575 17428983792,149585572681,1283829500408,11018563866669,94567658435392,
%U A015575 811634086816481,6965910986708808,59785458327752869,513113221555566992,4403833064083300281,37796230620444237208
%N A015575 Expansion of x/(1 - 8*x - 5*x^2).
%C A015575 Pisano period lengths: 1, 2, 3, 2, 4, 6, 21, 4, 9, 4, 120, 6, 56, 42, 12, 8, 16, 18, 360, 4, ... - _R. J. Mathar_, Aug 10 2012
%H A015575 Vincenzo Librandi, <a href="/A015575/b015575.txt">Table of n, a(n) for n = 0..1000</a>
%H A015575 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (8,5).
%F A015575 a(n) = 8*a(n-1) + 5*a(n-2).
%t A015575 Join[{a=0,b=1},Table[c=8*b+5*a;a=b;b=c,{n,100}]] (* _Vladimir Joseph Stephan Orlovsky_, Jan 17 2011 *)
%t A015575 LinearRecurrence[{8, 5}, {0, 1}, 30] (* _Vincenzo Librandi_, Nov 14 2012 *)
%t A015575 CoefficientList[Series[x/(1-8x-5x^2),{x,0,30}],x] (* _Harvey P. Dale_, Feb 28 2023 *)
%o A015575 (Sage) [lucas_number1(n,8,-5) for n in range(0, 20)] # _Zerinvary Lajos_, Apr 25 2009
%o A015575 (Magma) [n le 2 select n-1 else 8*Self(n-1) + 5*Self(n-2): n in [1..30]]; // _Vincenzo Librandi_, Nov 14 2012
%o A015575 (PARI) x='x+O('x^30); concat([0], Vec(x/(1-8*x-5*x^2))) \\ _G. C. Greubel_, Jan 06 2018
%K A015575 nonn,easy
%O A015575 0,3
%A A015575 _Olivier Gérard_