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 A186750 #30 Apr 11 2016 08:39:46
%S A186750 3,6,33,1086,1179393,1390967848446,1934791555410494424614913,
%T A186750 3743418362887760317407541271559358491868341997566
%N A186750 a(0) = 3; thereafter, a(n) = a(n-1)^2 - 3.
%C A186750 This is to A001566 as 3 is to 2 (subtrahend). Unlike A001566, which begins with 4 consecutive primes, this sequence can never be prime after a(0) = 3, because the first two terms are both multiples of 3, hence all later terms are. This is the k = 3 row of the array A(k, 0) = 3, A(k, n) = A(k, n-1)^2 - k; and A001566 is the k = 2 row. A003096(n+1) is the k = 1 row.
%H A186750 Vincenzo Librandi, <a href="/A186750/b186750.txt">Table of n, a(n) for n = 0..11</a>
%H A186750 <a href="/index/Aa#AHSL">Index entries for sequences of form a(n+1)=a(n)^2 + ...</a>
%F A186750 a(n) ~ c^(2^n), where c = 2.3959550115176494685408322564302422183669584045032057908382914927198090627... - _Vaclav Kotesovec_, Dec 18 2014
%t A186750 RecurrenceTable[{a[0] == 3, a[n] == a[n-1]^2 - 3}, a, {n, 0, 10}] (* _Vaclav Kotesovec_, Dec 18 2014 *)
%t A186750 Drop[Abs[NestList[#^2 - 3 &, 0, 9]], 1] (* _Alonso del Arte_, Apr 08 2016 *)
%Y A186750 Cf. A001566, A003096.
%K A186750 nonn,easy
%O A186750 0,1
%A A186750 _Jonathan Vos Post_, Feb 26 2011