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 A143042 #4 Mar 31 2012 10:26:07 %S A143042 660,2262,10836,67512,510873,4357756,39780102,376957389,3650049088, %T A143042 35810556535 %N A143042 10^n-th number divisible by exactly 4 distinct primes. %D A143042 J.-M. De Koninck, Ces nombres qui nous fascinent, Entry 455, pp 94, Ellipses, Paris 2008. %F A143042 a(n)=A033993(10^n). %Y A143042 Cf. A033993. %K A143042 more,nonn %O A143042 1,1 %A A143042 _Lekraj Beedassy_, Jul 18 2008 %E A143042 a(8)-a(10) from _Donovan Johnson_, Mar 30 2010