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 A121111 #10 Nov 25 2022 10:53:29 %S A121111 277777788888899,4996238671872,438939648,4478976,338688,27648,2688, %T A121111 768,336,54,20,0 %N A121111 Trajectory of 277777788888899 under "x -> product of digits of x" map. %C A121111 This is the smallest number of persistence 11 (cf. A003001). It is conjectured that no number has persistence greater than 11. %H A121111 N. J. A. Sloane, <a href="http://neilsloane.com/doc/persistence.html">The persistence of a number</a>, J. Recreational Math., 6 (1973), 97-98. %F A121111 a(n)=A121110(n-1), n>=3. [From _R. J. Mathar_, Aug 07 2008] %t A121111 NestWhileList[Times@@IntegerDigits[#]&,277777788888899,#>0&] (* _Harvey P. Dale_, Nov 25 2022 *) %Y A121111 Cf. A003001. %K A121111 nonn,fini,full,base %O A121111 1,1 %A A121111 _N. J. A. Sloane_, Aug 12 2006 %E A121111 Edited by _Charles R Greathouse IV_, Aug 05 2010