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 A090732 #26 Dec 07 2019 12:18:24
%S A090732 2,24,574,13752,329474,7893624,189117502,4530926424,108553116674,
%T A090732 2600743873752,62309299853374,1492822452607224,35765429562720002,
%U A090732 856877487052672824,20529294259701427774,491846184745781593752
%N A090732 a(n) = 24a(n-1) - a(n-2), starting with a(0) = 2 and a(1) = 24.
%H A090732 Indranil Ghosh, <a href="/A090732/b090732.txt">Table of n, a(n) for n = 0..723</a>
%H A090732 Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a>
%H A090732 <a href="/index/Rea#recur1">Index entries for recurrences a(n) = k*a(n - 1) +/- a(n - 2)</a>
%H A090732 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (24,-1).
%F A090732 a(n) = p^n + q^n, where p = 12 + sqrt(143) and q = 12 - sqrt(143). - _Tanya Khovanova_, Feb 06 2007
%F A090732 G.f.: (2-24*x)/(1-24*x+x^2). - _Philippe Deléham_, Nov 02 2008
%F A090732 a(n)=2*A077424(n). - _R. J. Mathar_, Sep 27 2014
%t A090732 a[0] = 2; a[1] = 24; a[n_] := 24a[n - 1] - a[n - 2]; Table[ a[n], {n, 0, 15}] (* _Robert G. Wilson v_, Jan 30 2004 *)
%t A090732 LinearRecurrence[{24,-1},{2,24},30] (* _Harvey P. Dale_, Sep 19 2011 *)
%o A090732 (Sage) [lucas_number2(n,24,1) for n in range(0,20)] # _Zerinvary Lajos_, Jun 26 2008
%o A090732 (PARI) a(n)=([0,1;-1,24]^n*[2;24])[1,1] \\ _Charles R Greathouse IV_, Feb 07 2017
%Y A090732 Cf. A056949, A077424.
%K A090732 easy,nonn
%O A090732 0,1
%A A090732 Nikolay V. Kosinov (kosinov(AT)unitron.com.ua), Jan 18 2004