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 A178552 #13 Aug 29 2025 08:07:06 %S A178552 2333,3313,3323,3331,3343,3373,3433,3533,3733,3833,5333,7333,10333, %T A178552 13033,13313,13331,13337,13339,13633,13933,16333,17333,19333,20333, %U A178552 23339,23633,23833,29333,30133,30313,30323,31033,31337,31393,32233,32303,32323,32353,32363,32533 %N A178552 Primes with exactly three 3's. %H A178552 Daniel Starodubtsev, <a href="/A178552/b178552.txt">Table of n, a(n) for n = 1..10000</a> %t A178552 Select[Prime[Range[3500]],Count[IntegerDigits[#],3]==3 &] (* _Stefano Spezia_, Aug 29 2025 *) %Y A178552 Cf. A038618, A178550, A178551, A178553-A178558. %K A178552 nonn,base,changed %O A178552 1,1 %A A178552 _Lekraj Beedassy_, May 29 2010 %E A178552 Missing a(26) = 23633 and a(27) = 23833 inserted by _Daniel Starodubtsev_, Mar 14 2020