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Smallest prime substring of n, or 0 if no such substring exists.
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%I #12 Jan 29 2014 07:53:54

%S 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 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 0,7,0,0,7,7,2,3,7,5,7,7,7,7,0,0,2,3,0,5

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

%C a(n) <= A047814(n);

%C a(n) = 0 iff A039997(n) = 0, cf. A062115;

%C a(n) = n iff n is prime and A039997(n) = 1.

%H Reinhard Zumkeller, <a href="/A211396/b211396.txt">Table of n, a(n) for n = 0..10000</a>

%o (Haskell)

%o import Data.List (isInfixOf)

%o a211396 n = if null ips then 0 else head ips

%o where ips = [p | p <- takeWhile (<= n) a000040_list,

%o show p `isInfixOf` show n]

%K nonn,base,look

%O 0,3

%A _Reinhard Zumkeller_, Feb 08 2013