%I #7 Oct 06 2019 18:33:21
%S 0,0,0,0,0,3,7,0,3,2,3,7,0,3,7,5,5,0,7,7,7,7,3,0,7,0,3,7,0,13,7,31,37,
%T 13,0,5,7,3,67,73,79,0,19,19,97,19,11,23,7,29,23,23,41,5,7,3,2,71,7,2,
%U 83,29,7,31,31,31,31,37,47,3,53,59,67,73,79,83,89,97,0,0,41,2,43,43,43
%N Largest proper substring of n-th prime that is prime (0 if none).
%e p(16)=53, largest prime substring is 5, so a(16)=5.
%Y See A033274 for the 'no prime substring' sequence.
%K nonn,base
%O 1,6
%A _N. J. A. Sloane_
%E More terms from _Patrick De Geest_, Jun 15 1998