A166573 Prime numbers containing the string 13.
13, 113, 131, 137, 139, 313, 613, 1013, 1213, 1301, 1303, 1307, 1319, 1321, 1327, 1361, 1367, 1373, 1381, 1399, 1613, 1913, 2113, 2131, 2137, 2213, 2713, 3137, 3313, 3413, 3613, 4013, 4133, 4139, 4513, 4813, 5113, 5413, 5813, 6113, 6131, 6133, 7013, 7213, 8513
Offset: 1
Links
- Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
- Eric Weisstein's World of Mathematics, Triskaidekaphobia
- Wikipedia, Triskaidekaphobia
Crossrefs
Programs
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Haskell
import Data.List (isInfixOf) a166573 n = a166573_list !! (n-1) a166573_list = filter (("13" `isInfixOf`) . show) a000040_list -- Reinhard Zumkeller, Nov 09 2011
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Mathematica
p13Q[n_] := Module[{idn = IntegerDigits[n]}, MemberQ[Partition[idn, 2, 1], {1, 3}]]; Select[Prime[Range[1000]], p13Q] (* Vincenzo Librandi, Sep 14 2012 *) Select[Prime[Range[1500]], ! StringFreeQ[ToString[#], "13"] &] (* Vincenzo Librandi, May 03 2015 *)
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PARI
contains(n,k)=my(N=digits(n),K=digits(k)); for(i=0,#N-#K, for(j=1,#K,if(N[i+j]!=K[j],next(2))); return(1)); 0 is(n)=isprime(n) && contains(n,13) \\ Charles R Greathouse IV, Jun 20 2014
Formula
a(n) ~ n log n. - Charles R Greathouse IV, Nov 09 2011
Extensions
Corrected (313 inserted) by R. J. Mathar, Nov 30 2009
Comments