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 A127890 #18 Aug 25 2020 22:21:45 %S A127890 7,79,797,7393,73939,739399,7393933,73939133 %N A127890 Largest n-digit right-truncatable prime. %C A127890 For a variant see the Howard reference. - _Alexander R. Povolotsky_, Dec 23 2007 %C A127890 Right-truncatable means that the integer part of successive divisions by 10 always yields primes (or zero). - _M. F. Hasler_, Nov 07 2018 %D A127890 Toby Howard, "Magic Pi - The Magic of Numbers", PC Advisor magazine, May 1998. %H A127890 I. O. Angell and H. J. Godwin, <a href="http://dx.doi.org/10.1090/S0025-5718-1977-0427213-2">On Truncatable Primes</a>, Math. Comput. 31, 265-267, 1977. %H A127890 Jens Fehlau, <a href="https://www.youtube.com/watch?v=5BFDdVqAFZE">73939133 - Probably the Most Interesting Prime Number [Part 1]</a> and <a href="https://www.youtube.com/watch?v=f2lEB4nMmyI">[Part 2]</a>, Flammable Maths videos (2020). %H A127890 <a href="/index/Tri#tprime">Index entries for sequences related to truncatable primes</a> %o A127890 (PARI) A127890=vector(8, n, p=concat(apply(t->primes([t, t+1]*10), if(n>1, p)));p[#p]) \\ _M. F. Hasler_, Nov 07 2018 %Y A127890 Cf. A024770, A050986, A127889. %K A127890 base,nonn,fini,full %O A127890 1,1 %A A127890 _Ray Chandler_, Feb 04 2007