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A211396 Smallest prime substring of n, or 0 if no such substring exists.

%I A211396 #12 Jan 29 2014 07:53:54
%S A211396 0,0,2,3,0,5,0,7,0,0,0,11,2,3,0,5,0,7,0,19,2,2,2,2,2,2,2,2,2,2,3,3,2,
%T A211396 3,3,3,3,3,3,3,0,41,2,3,0,5,0,7,0,0,5,5,2,3,5,5,5,5,5,5,0,61,2,3,0,5,
%U A211396 0,7,0,0,7,7,2,3,7,5,7,7,7,7,0,0,2,3,0,5
%N A211396 Smallest prime substring of n, or 0 if no such substring exists.
%C A211396 a(n) <= A047814(n);
%C A211396 a(n) = 0 iff A039997(n) = 0, cf. A062115;
%C A211396 a(n) = n iff n is prime and A039997(n) = 1.
%H A211396 Reinhard Zumkeller, <a href="/A211396/b211396.txt">Table of n, a(n) for n = 0..10000</a>
%o A211396 (Haskell)
%o A211396 import Data.List (isInfixOf)
%o A211396 a211396 n = if null ips then 0 else head ips
%o A211396    where ips = [p | p <- takeWhile (<= n) a000040_list,
%o A211396                     show p `isInfixOf` show n]
%K A211396 nonn,base,look
%O A211396 0,3
%A A211396 _Reinhard Zumkeller_, Feb 08 2013