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 A143765 #8 Dec 18 2014 08:17:06
%S A143765 1,-1,11,31,605,356975,127424725111,16237060566937994735039,
%T A143765 263642135854412795003324875413502371940690649,
%U A143765 69507175797876652622009028770643203522181284529919017784559264153993383198392412717393759
%N A143765 a(n+1) = a(n)^2 - 3*n*a(n) + n^2, a(1) = 1.
%C A143765 Let f(n+1,k) = f(n,k)^2 + k*n*f(n,k) + n^2, f(1, k) = 1:
%C A143765 f(n,0)=A143760(n), f(n,-1)=A143761(n), f(n,+1)=A143762(n),
%C A143765 f(n,-2)=A143763(n), f(n,+2)=A143764(n), f(n,-3)=a(n), f(n,+3)=A143766(n).
%H A143765 <a href="/index/Aa#AHSL">Index entries for sequences of form a(n+1)=a(n)^2 + ...</a> [From _Reinhard Zumkeller_, Sep 11 2008]
%F A143765 a(n) ~ c^(2^n), where c = 1.22112407764058519321076802441458002508833724488233983960016657090909521541... . - _Vaclav Kotesovec_, Dec 18 2014
%t A143765 RecurrenceTable[{a[n+1] == a[n]^2 - 3*n*a[n] + n^2, a[1] == 1}, a, {n, 1, 10}] (* _Vaclav Kotesovec_, Dec 18 2014 *)
%K A143765 sign
%O A143765 1,3
%A A143765 _Reinhard Zumkeller_, Sep 01 2008