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 A069573 #3 Dec 05 2013 19:55:15 %S A069573 9,89,989,8989,58989,658989,7658989,87658989,987658989,5987658989, %T A069573 15987658989,615987658989,1615987658989,71615987658989, %U A069573 571615987658989,8571615987658989,18571615987658989,918571615987658989 %N A069573 Largest n-digit number in which the k-th digit is a divisor or a multiple of k. %Y A069573 Cf. A069570, A069571, A069572. %K A069573 nonn,base %O A069573 1,1 %A A069573 _Amarnath Murthy_, Mar 24 2002