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 A015541 #41 Aug 04 2024 19:08:51
%S A015541 0,1,5,32,195,1199,7360,45193,277485,1703776,10461275,64232807,
%T A015541 394392960,2421594449,14868722965,91294775968,560554940595,
%U A015541 3441838134751,21133075257920,129758243232857,796722742969725,4891921417478624,30036666288181195
%N A015541 Expansion of x/(1 - 5*x - 7*x^2).
%C A015541 Pisano period lengths: 1, 3, 8, 6, 8, 24, 6, 6, 24, 24, 5, 24, 12, 6, 8, 12, 16, 24, 120, 24, ... - _R. J. Mathar_, Aug 10 2012
%H A015541 Vincenzo Librandi, <a href="/A015541/b015541.txt">Table of n, a(n) for n = 0..1000</a>
%H A015541 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (5,7).
%F A015541 a(n) = 5*a(n-1) + 7*a(n-2).
%t A015541 Join[{a=0,b=1},Table[c=5*b+7*a;a=b;b=c,{n,100}]] (* _Vladimir Joseph Stephan Orlovsky_, Jan 16 2011 *)
%t A015541 LinearRecurrence[{5, 7}, {0, 1}, 30] (* _Vincenzo Librandi_, Nov 13 2012 *)
%o A015541 (Sage) [lucas_number1(n,5,-7) for n in range(0, 21)] # _Zerinvary Lajos_, Apr 24 2009
%o A015541 (Magma) [n le 2 select n-1 else 5*Self(n-1) + 7*Self(n-2): n in [1..30]]; // _Vincenzo Librandi_, Nov 13 2012
%o A015541 (PARI) x='x+O('x^30); concat([0], Vec(x/(1-5*x-7*x^2))) \\ _G. C. Greubel_, Jan 24 2018
%Y A015541 Cf. A001076, A006190, A007482, A015520, A015521, A015523, A015524, A015525, A015528, A015529, A015530, A015531, A015532, A015533, A015534, A015535, A015536, A015537, A015443, A015447, A030195, A053404, A057087, A057088, A083858, A085939, A090017, A091914, A099012, A180222, A180226.
%K A015541 nonn,easy
%O A015541 0,3
%A A015541 _Olivier Gérard_