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 A154249 #18 Sep 08 2022 08:45:40
%S A154249 1,16,199,2272,25009,270640,2904727,31049152,331216993,3529670224,
%T A154249 37595354983,400334476960,4262416397329,45379597170544,
%U A154249 483115820080951,5143216082574208,54753855576573121,582898372518440080
%N A154249 a(n) = ( (8 + sqrt(7))^n - (8 - sqrt(7))^n )/(2*sqrt(7)).
%C A154249 lim_{n -> infinity} a(n)/a(n-1) = 8 + sqrt(7) = 10.6457513110....
%H A154249 G. C. Greubel, <a href="/A154249/b154249.txt">Table of n, a(n) for n = 1..750</a>
%H A154249 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (16, -57).
%F A154249 From _Philippe Deléham_, Jan 06 2009: (Start)
%F A154249 a(n) = 16*a(n-1)-57*a(n-2) for n>1, with a(0)=0, a(1)=1.
%F A154249 G.f.: x/(1 - 16*x + 57*x^2). (End)
%F A154249 E.g.f.: (1/sqrt(7))*exp(8*x)*sinh(sqrt(7)*x). - _G. C. Greubel_, Sep 08 2016
%p A154249 seq(expand((8+sqrt(7))^n-(8-sqrt(7))^n)/sqrt(28), n = 1 .. 20); # _Emeric Deutsch_, Jan 08 2009
%t A154249 Join[{a=1,b=16},Table[c=16*b-57*a;a=b;b=c,{n,40}]] (* _Vladimir Joseph Stephan Orlovsky_, Feb 08 2011 *)
%t A154249 LinearRecurrence[{16,-57},{1,16},25] (* or *) Table[( (8 + sqrt(7))^n - (8 - sqrt(7))^n )/(2*sqrt(7)), {n,1,25}] (* _G. C. Greubel_, Sep 08 2016 *)
%o A154249 (Magma) Z<x>:=PolynomialRing(Integers()); N<r>:=NumberField(x^2-7); S:=[ ((8+r)^n-(8-r)^n)/(2*r): n in [1..18] ]; [ Integers()!S[j]: j in [1..#S] ]; // _Klaus Brockhaus_, Jan 07 2009
%Y A154249 Cf. A010465 (decimal expansion of square root of 7).
%K A154249 nonn
%O A154249 1,2
%A A154249 Al Hakanson (hawkuu(AT)gmail.com), Jan 05 2009
%E A154249 Extended by _Emeric Deutsch_ and _Klaus Brockhaus_, Jan 08 2009
%E A154249 Edited by _Klaus Brockhaus_, Oct 06 2009