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 A146965 #25 Sep 08 2022 08:45:38
%S A146965 1,5,32,230,1724,13100,99968,763880,5839376,44643920,341330432,
%T A146965 2609713760,19953189824,152557050560,1166413088768,8918103977600,
%U A146965 68185604178176,521330170184960,3985960826642432,30475665203095040
%N A146965 a(n) = 10*a(n-1) - 18*a(n-2) with a(0)=1, a(1)=5.
%C A146965 The Mathematica program implements the formula provided by Deleham and Brockhaus. - _Harvey P. Dale_, Feb 17 2011
%H A146965 Vincenzo Librandi, <a href="/A146965/b146965.txt">Table of n, a(n) for n = 0..145</a>
%H A146965 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (10,-18).
%F A146965 a(n) = ((5 + sqrt(7))^n + (5 - sqrt(7))^n)/2.
%F A146965 G.f.: (1-5*x)/(1-10*x+18*x^2). - _Philippe Deléham_ and _Klaus Brockhaus_, Nov 05 2008
%F A146965 a(n) = (Sum_{k=0..n} A098158(n,k)*5^(2*k)*7^(n-k))/5^n. - _Philippe Deléham_, Nov 06 2008
%F A146965 E.g.f.: exp(5*x)*cosh(sqrt(7)*x). - _G. C. Greubel_, Jan 08 2020
%p A146965 seq(coeff(series((1-5*x)/(1-10*x+18*x^2), x, n+1), x, n), n = 0..30); # _G. C. Greubel_, Jan 08 2020
%t A146965 Transpose[NestList[{#[[2]],10#[[2]]-18#[[1]]}&,{1,5},20]][[1]] (* _Harvey P. Dale_, Feb 17 2011 *)
%t A146965 LinearRecurrence[{10,-18},{1,5},30] (* _Harvey P. Dale_, Aug 27 2013 *)
%o A146965 (Magma) Z<x>:= PolynomialRing(Integers()); N<r7>:=NumberField(x^2-7); S:=[ ((5+r7)^n+(5-r7)^n)/2: n in [0..19] ]; [ Integers()!S[j]: j in [1..#S] ]; // _Klaus Brockhaus_, Nov 05 2008
%o A146965 (PARI) my(x='x+O('x^30)); Vec((1-5*x)/(1-10*x+18*x^2)) \\ _G. C. Greubel_, Jan 08 2020
%o A146965 (Sage)
%o A146965 def A146965_list(prec):
%o A146965 P.<x> = PowerSeriesRing(ZZ, prec)
%o A146965 return P( (1-5*x)/(1-10*x+18*x^2) ).list()
%o A146965 A146965_list(30) # _G. C. Greubel_, Jan 08 2020
%o A146965 (GAP) a:=[1,5];; for n in [3..30] do a[n]:=10*a[n-1]-18*a[n-2]; od; a; # _G. C. Greubel_, Jan 08 2020
%K A146965 nonn
%O A146965 0,2
%A A146965 Al Hakanson (hawkuu(AT)gmail.com), Nov 03 2008
%E A146965 Extended beyond a(7) by _Klaus Brockhaus_, Nov 05 2008
%E A146965 Name from _Philippe Deléham_ and _Klaus Brockhaus_, Nov 05 2008