%I #24 Sep 02 2023 17:00:09
%S 3,7,47,2207,4481,26111,189017,67271,11815633,606737,708641,354023,
%T 125332284527,51939720282500417,18062107820423,1376080289340623571113,
%U 4012316132900773615751,983669740542169,4443427285129103,19744046038229790810567377584607,4300749014896245437702886338812998834884967953,41572359968343362282287450730112204489086145685200294134959430572332688727999
%N a(0) = 3; for n > 0, a(n) is the greatest prime factor of a(n-1)^2 - 2.
%C Is this sequence unbounded? [_Charles R Greathouse IV_, Dec 29 2011]
%H Dennis Langdeau, <a href="/A031440/b031440.txt">Table of n, a(n) for n = 0..23</a>
%t NestList[FactorInteger[#^2-2][[-1,1]]&,3,22] (* _Harvey P. Dale_, Jan 10 2013 *)
%K nonn,nice
%O 0,1
%A _Yasutoshi Kohmoto_
%E More terms from Dennis Langdeau (dlangdea(AT)sfu.ca), Jun 26 2006