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 A269575 #9 Apr 17 2016 12:25:30 %S A269575 101,191,1091,10091,100000000091,1000000000091,1000000000000091 %N A269575 Primes of the form 10^n + 91. %F A269575 a(n)= 10^A110918(n) + 91. %t A269575 Select[10^Range[10] + 91, PrimeQ] (* _Alonso del Arte_, Mar 01 2016 *) %o A269575 (PARI) lista(nn) = for(n=1, nn, if(ispseudoprime(p=10^n+91), print1(p, ", "))); \\ _Altug Alkan_, Apr 16 2016 %Y A269575 Cf. A110918. %K A269575 nonn %O A269575 1,1 %A A269575 _Mironov Alexander_, Mar 01 2016