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 A096912 #9 Dec 15 2017 17:36:44 %S A096912 8,16,20,62,64,76,100,142,230,670,2230,167644 %N A096912 Numbers n such that 111*10^n+1 is prime. %C A096912 a(1) through a(11) have been proved to be prime with WinPFGW. %o A096912 (PARI) is(n)=ispseudoprime(111*10^n+1) \\ _Charles R Greathouse IV_, Jun 12 2017 %K A096912 more,nonn %O A096912 1,1 %A A096912 _Jason Earls_, Aug 17 2004 %E A096912 a(12) from _Predrag Kurtovic_, May 24 2015