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 A173483 #3 Mar 30 2012 19:00:22 %S A173483 90,900,9000,90000,900000,9000000,70000000,900000000,9000000000, %T A173483 90000000000,0,9000000000000,0,700000000000000,9000000000000000, %U A173483 90000000000000000,0,9000000000000000000,0,900000000000000000000 %N A173483 a(n) = the largest (n+1)-digit number ending in n zeros that is divisible by n, else 0. %C A173483 See A173478 - A173486. %F A173483 If A006530(n) > 7, then a(n)=0. [From _R. J. Mathar_, Mar 12 2010] %K A173483 nonn,base %O A173483 1,1 %A A173483 _Jaroslav Krizek_, Feb 19 2010 %E A173483 More terms from _R. J. Mathar_, Mar 12 2010