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 A282180 #14 Sep 08 2022 08:46:18
%S A282180 8,488,116212808,1569502402942700328379688,
%T A282180 3866214585126515728777536857817155683642224883875510905654220958052649608
%N A282180 a(n+1) = a(n)*(a(n)^2 - 3) with a(0) = 8.
%H A282180 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.
%F A282180 a(n) = (4 + sqrt(15))^(3^n) + (4 - sqrt(15))^(3^n). - _Bruno Berselli_, Feb 10 2017
%F A282180 a(n) = -2*cos(3^n * arccos(-4)). - _Daniel Suteu_, Feb 10 2017
%t A282180 RecurrenceTable[{a[0] == 8, a[n] == a[n-1]^3 - 3 a[n-1]}, a, {n, 8}]
%o A282180 (Magma) [n eq 1 select 8 else Self(n-1)^3 - 3*Self(n-1): n in [1..6]];
%Y A282180 Cf. similar sequences with initial value k: A001999 (k=3), A219160 (k=4), A219161 (k=5), A112845 (k=6), A002000 (k=7), this sequence (k=8), A282181 (k=9), A006242 (k=10), A006243 (k=198).
%K A282180 nonn
%O A282180 0,1
%A A282180 _Vincenzo Librandi_, Feb 10 2017