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 A189748 #32 Feb 18 2024 03:34:19
%S A189748 5,4,40,216,1240,7064,40280,229656,1309400,7465624,42565720,242691096,
%T A189748 1383718360,7889356184,44981654360,256465696536,1462255100120,
%U A189748 8337138286744,47534711834200,271022112317976,1545249408926680,8810335493905304,50232675105233240
%N A189748 a(n) = 5*a(n-1) + 4*a(n-2) with a(1)=5, a(2)=4.
%H A189748 Vincenzo Librandi, <a href="/A189748/b189748.txt">Table of n, a(n) for n = 1..100</a>
%H A189748 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (5,4).
%F A189748 G.f.: x*(5-21*x)/(1-5*x-4*x^2). - _Bruno Berselli_, May 24 2011
%t A189748 LinearRecurrence[{5,4},{5,4},40]
%o A189748 (Maxima) a[1]:5$ a[2]:4$ a[n]:=5*a[n-1]+4*a[n-2]$ makelist(a[n], n, 1, 23); /* _Bruno Berselli_, May 24 2011 */
%Y A189748 Cf. A000045, A000079, A105476, A159612, A080040, A135522, A103435, A189732, A189734, A189735, A189736, A189737, A189738, A189739, A189741, A189742, A189743, A189744, A189745, A189746, A189747, A189749.
%K A189748 nonn,easy
%O A189748 1,1
%A A189748 _Harvey P. Dale_, Apr 26 2011