%I #3 Mar 30 2012 16:49:57
%S 111111111111111111111,10101,210,111,41,33,30,25,23,21
%N a(n) = 21 written in base n.
%C The next term contains a non-decimal digit.
%K nonn
%O 1,1
%A _N. J. A. Sloane_, Jun 04 2004