%I #2 Oct 02 2013 15:47:28
%S 21,411,111,1111,11111,2111111,1111111,211111111,2111111111,
%T 21111111111,11111111111,4111111111111,121111111111111,
%U 511111111111111,2111111111111111,81111111111111111,11111111111111111
%N Smallest semiprime ending in exactly n 1's.
%e a(2)=411 is a term because 411 is the smallest semiprime ending in exactly two 1's.
%K base,nonn
%O 1,1
%A _Shyam Sunder Gupta_, May 12 2005