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 A095688 #30 Aug 10 2025 16:52:25
%S A095688 1,2,3,17,25,81,140,142,152,280,291,406,4209,4785,8474,9550,9596,
%T A095688 21773,22352,24938,38428,48526,65426,75441,76705
%N A095688 Numbers k such that 10^k + 13 is prime.
%C A095688 No other terms <= 100000. - _Robert Price_, Mar 03 2011
%t A095688 lst={};Do[If[PrimeQ[10^n+13], AppendTo[lst, n]], {n, 10^3}];lst (* _Vladimir Joseph Stephan Orlovsky_, Aug 20 2008 *)
%o A095688 (PARI) for(n=1,1e4,if(ispseudoprime(10^n+13),print1(n", "))) \\ _Charles R Greathouse IV_, Jul 19 2011
%Y A095688 Cf. A095680 (the actual primes).
%K A095688 nonn,more,hard
%O A095688 1,2
%A A095688 _Jason Earls_, Jul 05 2004
%E A095688 More terms from _Ryan Propper_, Sep 07 2005
%E A095688 5 more terms from _Jason Earls_, Feb 08 2008
%E A095688 a(23)=65426 from _Robert Price_, Jan 09 2011
%E A095688 a(24) and a(25) = 75441,76705 from _Robert Price_, Jan 29 2011