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 A108729 #11 Aug 20 2021 04:21:17 %S A108729 1,3,7,9,21,27,57,81,111,189,243,333,441,729,777,999,1161,1701,2109, %T A108729 2187,2529,2709,2763,2793,2997 %N A108729 Numbers k that divide A076127(k); or k such that A076127(k) is a Niven number. %e A108729 a(2)=3 because A076127(3)=101001 and 101001/3 = 33667. %Y A108729 Cf. A005349, A076127. %K A108729 base,nonn,more %O A108729 1,2 %A A108729 _Jason Earls_, Jun 21 2005 %E A108729 More terms from _David Wasserman_, May 22 2008