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 A031991 #5 Apr 03 2023 10:36:09 %S A031991 2,13,107,1069,10247,102367,1023487,10235749,102346897 %N A031991 Smallest n-digit norep emirp. %H A031991 C. K. Caldwell, Prime Curios, <a href="https://t5k.org/curios/page.php?number_id=6668">Entry 102346897</a> %Y A031991 Cf. A046732, A030540. %K A031991 nonn,base,fini,full %O A031991 1,1 %A A031991 _Harvey P. Dale_