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 A173478 #2 Mar 30 2012 19:00:22 %S A173478 1,10,300,1000,10000,300000,7000000,10000000,900000000,1000000000, %T A173478 110000000000,300000000000,13000000000000,70000000000000, %U A173478 300000000000000 %N A173478 a(n) = the smallest number ending in n-1 zeros divisible by n. %C A173478 See A173478 - A173486. %K A173478 nonn %O A173478 1,2 %A A173478 _Jaroslav Krizek_, Mar 04 2010