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 A015588 #34 Mar 18 2024 11:23:46
%S A015588 0,1,10,103,1060,10909,112270,1155427,11891080,122377081,1259444050,
%T A015588 12961571743,133394049580,1372825211029,14128434259030,
%U A015588 145402818223387,1496413485010960,15400343304779761,158492673502830490,1631127764942644183,16786755669934933300
%N A015588 Expansion of x/(1 - 10*x - 3*x^2).
%H A015588 Vincenzo Librandi, <a href="/A015588/b015588.txt">Table of n, a(n) for n = 0..1000</a>
%H A015588 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (10,3).
%F A015588 a(n) = 10*a(n-1) + 3*a(n-2).
%t A015588 Join[{a=0,b=1},Table[c=10*b+3*a;a=b;b=c,{n,50}]] (* _Vladimir Joseph Stephan Orlovsky_, Mar 26 2011 *)
%t A015588 LinearRecurrence[{10, 3}, {0, 1}, 30] (* _Vincenzo Librandi_, Nov 15 2012 *)
%o A015588 (SageMath) [lucas_number1(n,10,-3) for n in range(0, 20)] # _Zerinvary Lajos_, Apr 26 2009
%o A015588 (Magma) [n le 2 select n-1 else 10*Self(n-1) + 3*Self(n-2): n in [1..30]]; // _Vincenzo Librandi_, Nov 15 2012
%o A015588 (PARI) x='x+O('x^30); concat([0], Vec(x/(1-10*x-3*x^2))) \\ _G. C. Greubel_, Jan 06 2018
%Y A015588 Cf. A000045, A015518.
%K A015588 nonn,easy
%O A015588 0,3
%A A015588 _Olivier Gérard_