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 A097649 #20 Aug 08 2019 06:39:07 %S A097649 1,11,101,1111,10291,100651,1004251,10165751,100064101,1000078501, %T A097649 10000222501,100062501601,1000062516001,10000062660001, %U A097649 100002441447211,1003922328562757,10000390625025601,100000002482366251 %N A097649 Duplicate of A072075. %C A097649 Name was: a(n) is the smallest number m such that phi(m)=10^n. %K A097649 dead %O A097649 0,2