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 A015574 #36 Dec 18 2023 12:19:09
%S A015574 0,1,8,67,560,4681,39128,327067,2733920,22852561,191022248,1596735667,
%T A015574 13346952080,111565823641,932567445368,7795237033867,65159598607040,
%U A015574 544662499957921,4552778795484488,38056217863749667,318108079296450800,2659033287962855401,22226590541592195608
%N A015574 Expansion of x/(1 - 8*x - 3*x^2).
%C A015574 Pisano period lengths: 1, 2, 2, 4, 4, 2, 24, 4, 6, 4, 120, 4, 84, 24, 4, 8, 16, 6, 171, 4, ... - _R. J. Mathar_, Aug 10 2012
%H A015574 Vincenzo Librandi, <a href="/A015574/b015574.txt">Table of n, a(n) for n = 0..1000</a>
%H A015574 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (8,3).
%F A015574 a(n) = 8*a(n-1) + 3*a(n-2).
%t A015574 LinearRecurrence[{8, 3}, {0, 1}, 30] (* _Vincenzo Librandi_, Nov 14 2012 *)
%o A015574 (Sage) [lucas_number1(n,8,-3) for n in range(0, 20)] # _Zerinvary Lajos_, Apr 25 2009
%o A015574 (Magma) [n le 2 select n-1 else 8*Self(n-1) + 3*Self(n-2): n in [1..30]]; // _Vincenzo Librandi_, Nov 14 2012
%o A015574 (PARI) x='x+O('x^30); concat([0], Vec(x/(1-8*x-3*x^2))) \\ _G. C. Greubel_, Jan 06 2018
%K A015574 nonn,easy
%O A015574 0,3
%A A015574 _Olivier Gérard_