%I #2 Oct 02 2013 15:47:26
%S 15,55,1555,50555,505555,1555555,55255555,355555555,5155555555,
%T 52555555555,155555555555,1555555555555,25555555555555,
%U 155555555555555,5155555555555555,25555555555555555,505555555555555555
%N Smallest semiprime containing exactly n 5's.
%e a(2)=55 because 55 is the smallest semiprime containing exactly two 5's.
%K base,nonn
%O 1,1
%A _Shyam Sunder Gupta_, Apr 24 2005