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 A333718 #32 Jul 09 2022 21:47:56
%S A333718 1,46,2161,101521,4769326,224056801,10525900321,494493258286,
%T A333718 23230657239121,1091346396980401,51270050000839726,
%U A333718 2408601003642486721,113152977121196036161,5315781323692571212846,249728569236429650967601,11731926972788501024264401,551150839151823118489459246
%N A333718 a(n) = L(8*n+4)/7, where L=A000032 (the Lucas sequence).
%C A333718 a(n) is the denominator of the continued fraction [3*sqrt(5), 3*sqrt(5),..., 3*sqrt(5)] with 2n+1 terms.
%C A333718 a(n) = (2/7)*T(2*n+1, 7/2), where T(n,x) denotes the n-th Chebyshev polynomial of the first kind. - _Peter Bala_, Jul 08 2022
%H A333718 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (47,-1).
%F A333718 a(n) = 47*a(n-1) - a(n-2) for n>2.
%F A333718 G.f.: (1-x)/(1-47*x+x^2). - _R. J. Mathar_, Sep 03 2020
%e A333718 The continued fraction [3*sqrt(5), 3*sqrt(5), 3*sqrt(5)] with 2*1 + 1 terms equals 141*sqrt(5)/46, and 46 is our a(1) term.
%t A333718 Table[LucasL[8 n + 4]/7, {n, 0, 20}]
%Y A333718 Cf. A000032, A049685, first differences of A049668.
%K A333718 nonn,easy
%O A333718 0,2
%A A333718 _Greg Dresden_ and _Tracy Z. Wu_, Sep 03 2020