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 A121033 #17 Feb 26 2024 09:20:46 %S A121033 13,130,1131,1300,1313,1326,1339,1352,1365,1378,1391,2132,2613,3133, %T A121033 3913,4134,5135,5213,6136,6513,7137,7813,8138,9113,9139,10413,11310, %U A121033 11323,11336,11349,11362,11375,11388,11713,13000,13013,13026,13039 %N A121033 Multiples of 13 containing a 13 in their decimal representation. %H A121033 Paolo Xausa, <a href="/A121033/b121033.txt">Table of n, a(n) for n = 1..10000</a> %H A121033 <a href="/index/Ar#10-automatic">Index entries for 10-automatic sequences</a>. %t A121033 Select[13*Range[2000], StringContainsQ[IntegerString[#], "13"] &] (* _Paolo Xausa_, Feb 25 2024 *) %o A121033 (PARI) is(n)=if(n%13, return(0)); while(n>12, if(n%100==13, return(1)); n\=10); 0 \\ _Charles R Greathouse IV_, Feb 12 2017 %Y A121033 Cf. A121041, A008595, A011531, A121022, A121023, A121024, A121025, A121026, A121027, A121028, A121029, A121030, A121031, A121032, A121034, A121035, A121036, A121037, A121038, A121039, A121040. %K A121033 nonn,base,easy %O A121033 1,1 %A A121033 _Reinhard Zumkeller_, Jul 21 2006 %E A121033 Corrected by _T. D. Noe_, Oct 25 2006