%I #4 Mar 30 2012 19:00:24
%S 1,-1,-9,9999,99900039992000799967
%N a(1) = 1, for n >= 2: a(n) = (a(n-1)-1)^n - 1.
%C a(6) has 120 digits.
%e For n = 4: a(4) = (-9-1)^4 - 1 = 9999.
%K sign
%O 1,3
%A _Jaroslav Krizek_, Nov 03 2010