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 A199997 #9 Aug 03 2014 14:01:36
%S A199997 68889,68898,68988,69888,86889,86898,86988,88689,88698,88869,88896,
%T A199997 88968,88986,89688,89868,89886,96888,98688,98868,98886,168889,168898,
%U A199997 168988,169888,186898,186988,188689,188698,188896,188968,188986,189688,189868,189886,196888
%N A199997 Composite numbers whose multiplicative persistence is 7.
%C A199997 Complement of A046507 with respect to A046516.
%e A199997 68889 -> [ 27648 ][ 2688 ][ 768 ][ 336 ][ 54 ][ 20 ][ 0 ] -> one digit in seven steps.
%t A199997 persistence[n_] := Module[{cnt = 0, k = n}, While[k > 9, cnt++; k = Times @@ IntegerDigits[k]]; cnt]; Select[Range[300000], ! PrimeQ[#] && persistence[#] == 7 &] (* _T. D. Noe_, Nov 23 2011 *)
%Y A199997 Cf. A046507 (primes whose multiplicative persistence is 7).
%K A199997 nonn,base
%O A199997 1,1
%A A199997 _Jaroslav Krizek_, Nov 13 2011