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 A075083 #6 Feb 14 2016 08:53:14
%S A075083 0,0,0,4,0,6,0,8,9,10,0,21,0,14,51,16,0,81,91,20,21,22,32,42,52,62,72,
%T A075083 82,92,30,0,32,33,34,35,63,0,38,93,40,14,42,34,44,54,64,74,84,94,50,
%U A075083 51,52,35,54,55,65,75,85,95,60,16,62,63,64,65,66,76,86,96,70,0,72,0,74,75
%N A075083 Largest composite number formed by permuting the digits of n, or 0 if no such number exists.
%t A075083 Table[Max[Select[FromDigits/@Permutations[IntegerDigits[n]], CompositeQ]],{n,80}]/.(-\[Infinity]->0) (* _Harvey P. Dale_, Feb 14 2016 *)
%Y A075083 Cf. A047814.
%K A075083 easy,nonn,base
%O A075083 1,4
%A A075083 _Amarnath Murthy_, Sep 11 2002
%E A075083 More terms from _David Wasserman_, Jan 16 2005