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 A350919 #13 Jul 19 2024 17:03:52
%S A350919 9,9,14,29,69,174,449,1169,3054,7989,20909,54734,143289,375129,982094,
%T A350919 2571149,6731349,17622894,46137329,120789089,316229934,827900709,
%U A350919 2167472189,5674515854,14856075369,38893710249,101825055374,266581455869,697919312229,1827176480814,4783610130209,12523653909809,32787351599214,85838400887829,224727851064269
%N A350919 a(0) = 9, a(1) = 9, and a(n) = 3*a(n-1) - a(n-2) - 4 for n >= 2.
%C A350919 One of 10 linear second-order recurrence sequences satisfying (a(n)*a(n-1)-1) * (a(n)*a(n+1)-1) = (a(n)+1)^4 and together forming A350916.
%H A350919 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (4,-4,1).
%F A350919 a(n) = 5*A032908(n) - 1. - _Hugo Pfoertner_, Jan 22 2022
%F A350919 G.f.: (3 - 2*x)*(3 - 7*x)/((1 - x)*(1 - 3*x + x^2)). - _Stefano Spezia_, Jan 22 2022
%F A350919 a(n) = 5*A001519(n) +4. - _R. J. Mathar_, Feb 07 2022
%t A350919 nxt[{a_,b_}]:={b,3b-a-4}; NestList[nxt,{9,9},40][[;;,1]] (* or *) LinearRecurrence[{4,-4,1},{9,9,14},40] (* _Harvey P. Dale_, Jul 19 2024 *)
%Y A350919 Cf. A032908, A350916.
%Y A350919 Other sequences satisfying (a(n)*a(n-1)-1) * (a(n)*a(n+1)-1) = (a(n)+1)^4: A103974, A350917, A350920, A350921, A350922, A350923, A350924, A350925, A350926.
%K A350919 nonn,easy
%O A350919 0,1
%A A350919 _Max Alekseyev_, Jan 22 2022