Thanks for the link, I dug a little more and came across [1] which mentions a contribution by erdos to the effect that persistence might not be bounded. I guess

Thanks for the link, I dug a little more and came across [1] which mentions a contribution by erdos to the effect that persistence might not be bounded. I guess I might spend some time to figure out number 12 :) [1] http://web.archive.org/web/20050214141815/http://www.wschnei.de/digit-related-numbers/persistence.html http://web.archive.org/web/20050214141815/http://www.wschnei...