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%I #11 Apr 09 2014 10:16:57
%S 1,1,2,4,20,160020
%N a(1) = a(2) = 1; a(n+2) = a(n+1) + a(n+1)^a(n).
%C The next term is 105 digits long.
%t Join[{a=1,b=1},Table[c=b+b^a;a=b;b=c,{n,5}]] (* _Vladimir Joseph Stephan Orlovsky_, Apr 13 2011 *)
%Y Cf. A058523.
%K easy,nonn
%O 1,3
%A _Leroy Quet_, Dec 21 2000