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 A027896 #14 Jun 21 2017 22:01:49 %S A027896 1,3,9,21649,64947,194841,513239,1539717,4619151,11111111111, %T A027896 33333333333,99999999999 %N A027896 Divisors of 10^11 - 1. %H A027896 <a href="/index/Di#divisors">Index entries for sequences related to divisors of numbers</a> %t A027896 Divisors[10^11 - 1] (* _Wesley Ivan Hurt_, Jan 29 2017 *) %o A027896 (PARI) divisors(10^11-1) \\ _Charles R Greathouse IV_, Jun 21 2017 %K A027896 nonn,fini,full,easy %O A027896 1,2 %A A027896 _N. J. A. Sloane_