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 A219161 #17 Apr 23 2019 15:16:32
%S A219161 5,110,1330670,2356194280407770990,
%T A219161 13080769480548649962914459850235688797656360638877986030
%N A219161 Recurrence equation a(n+1) = a(n)^3 - 3*a(n) with a(0) = 5.
%C A219161 For some general remarks on this recurrence see A001999.
%C A219161 The next term (a(5)) has 166 digits. - _Harvey P. Dale_, Apr 23 2019
%H A219161 G. C. Greubel, <a href="/A219161/b219161.txt">Table of n, a(n) for n = 0..6</a>
%H A219161 E. B. Escott, <a href="http://www.jstor.org/stable/2301484">Rapid method for extracting a square root</a>, Amer. Math. Monthly, 44 (1937), 644-646.
%H A219161 N. J. Fine, <a href="http://www.jstor.org/stable/2321014">Infinite products for k-th roots</a>, Amer. Math. Monthly Vol. 84, No. 8, Oct. 1977, 629-630.
%F A219161 a(n) = (1/2*(5 + sqrt(21)))^(3^n) + (1/2*(5 - sqrt(21)))^(3^n).
%F A219161 Product_{n = 0..inf} (1 + 2/(a(n) - 1)) = sqrt(7/3).
%F A219161 a(n) = 2*T(3^n,5/2), where T(n,x) denotes the n-th Chebyshev polynomial of the first kind. Cf. A001999. - Peter Bala, Feb 01 2017
%t A219161 RecurrenceTable[{a[n] == a[n - 1]^3 - 3*a[n - 1], a[0] == 5}, a, {n,
%t A219161 0, 5}] (* _G. C. Greubel_, Dec 30 2016 *)
%t A219161 NestList[#^3-3#&,5,5] (* _Harvey P. Dale_, Apr 23 2019 *)
%Y A219161 Cf. A001999, A112845, A219160.
%K A219161 nonn,easy
%O A219161 0,1
%A A219161 _Peter Bala_, Nov 13 2012