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 A239661 #17 Jun 14 2014 08:05:49 %S A239661 1,3,9,11,33,99,121,363,1089 %N A239661 Divisors of 1089. %C A239661 Divisors of 33^2. %C A239661 The sum of divisors of 1089 is equal to 1729, the Hardy-Ramanujan number: A000203(1089) = A001235(1) = 1729. %C A239661 The aliquot divisors of 1089 are also the powers of 3 written in base 26, see A004668. %C A239661 Also 1089 is widely used in magic tricks because it can be produced from any two three-digit numbers (see Links section). %H A239661 Wikipedia, <a href="http://en.wikipedia.org/wiki/1089 (number)">1089 (number)</a> %e A239661 Sigma(1089) = 1 + 3 + 9 + 11 + 33 + 99 + 121 + 363 + 1089 = 1729. %t A239661 Divisors[1089] (* _Wesley Ivan Hurt_, Jun 13 2014 *) %o A239661 (PARI) divisors(1089) \\ _Michel Marcus_, Jun 14 2014 %Y A239661 Cf. A000203, A001235, A004668. %K A239661 nonn,easy,fini,full %O A239661 1,2 %A A239661 _Omar E. Pol_, Jun 10 2014