This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A166573 #31 Feb 16 2025 08:33:11 %S A166573 13,113,131,137,139,313,613,1013,1213,1301,1303,1307,1319,1321,1327, %T A166573 1361,1367,1373,1381,1399,1613,1913,2113,2131,2137,2213,2713,3137, %U A166573 3313,3413,3613,4013,4133,4139,4513,4813,5113,5413,5813,6113,6131,6133,7013,7213,8513 %N A166573 Prime numbers containing the string 13. %H A166573 Reinhard Zumkeller, <a href="/A166573/b166573.txt">Table of n, a(n) for n = 1..10000</a> %H A166573 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Triskaidekaphobia.html">Triskaidekaphobia</a> %H A166573 Wikipedia, <a href="http://en.wikipedia.org/wiki/Triskaidekaphobia">Triskaidekaphobia</a> %F A166573 a(n) ~ n log n. - _Charles R Greathouse IV_, Nov 09 2011 %t A166573 p13Q[n_] := Module[{idn = IntegerDigits[n]}, MemberQ[Partition[idn, 2, 1], {1, 3}]]; Select[Prime[Range[1000]], p13Q] (* _Vincenzo Librandi_, Sep 14 2012 *) %t A166573 Select[Prime[Range[1500]], ! StringFreeQ[ToString[#], "13"] &] (* _Vincenzo Librandi_, May 03 2015 *) %o A166573 (Haskell) %o A166573 import Data.List (isInfixOf) %o A166573 a166573 n = a166573_list !! (n-1) %o A166573 a166573_list = filter (("13" `isInfixOf`) . show) a000040_list %o A166573 -- _Reinhard Zumkeller_, Nov 09 2011 %o A166573 (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 %o A166573 is(n)=isprime(n) && contains(n,13) \\ _Charles R Greathouse IV_, Jun 20 2014 %Y A166573 Complement of A076805 with respect to A000040. %Y A166573 Cf. A166571, A166572, A166579, A166580, A166581, A166582. %K A166573 nonn,base %O A166573 1,1 %A A166573 _Vincenzo Librandi_, Nov 01 2009 %E A166573 Corrected (313 inserted) by _R. J. Mathar_, Nov 30 2009