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 A198377 #9 Mar 30 2012 19:00:25 %S A198377 0,10,25,39,77,679,6788,68889,2677889,26888999,3778889989, %T A198377 277777788888899 %N A198377 Smallest nonprime number with multiplicative persistence n. %C A198377 Probably finite sequence. The multiplicative persistence of a number is the number of times you need to multiply the digits together before reaching a single digit. %e A198377 For n=4, a(4) = 39 because 39 is the smallest nonprime number with multiplicative persistence 3: 39 -> 27 -> 14 -> 4. %Y A198377 Cf. A046500 (smallest prime with multiplicative persistence n). %K A198377 nonn,base %O A198377 0,2 %A A198377 _Jaroslav Krizek_, Oct 23 2011