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 A046517 #27 Feb 16 2025 08:32:39 %S A046517 2677889,2677898,2677988,2678789,2678798,2678879,2678897,2678978, %T A046517 2678987,2679788,2679878,2679887,2687789,2687798,2687879,2687897, %U A046517 2687978,2687987,2688779,2688797,2688977,2689778,2689787,2689877 %N A046517 Numbers with multiplicative persistence value 8. %H A046517 Daniel Mondot, <a href="/A046517/b046517.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..1000 from Robert Israel) %H A046517 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MultiplicativePersistence.html">Multiplicative Persistence</a> %e A046517 2677889 -> [ 338688 ][ 27648 ][ 2688 ][ 768 ][ 336 ][ 54 ][ 20 ][ 0 ] -> one digit in eight steps. %p A046517 mp:= proc(n) option remember; %p A046517 if n <= 9 then return 0 fi; %p A046517 1+procname(convert(convert(n,base,10),`*`)) %p A046517 end proc: %p A046517 select(mp=8, [$1..4000000]); # _Robert Israel_, Feb 12 2019 %t A046517 okQ[n_]:=Length[NestWhileList[Times@@IntegerDigits[#]&, n,IntegerLength[ #]>1&]]==9; Select[Range[2700000],okQ] (* _Harvey P. Dale_, Jan 29 2011 *) %Y A046517 Cf. A003001, A014120, A046508. %K A046517 nonn,base %O A046517 1,1 %A A046517 _Patrick De Geest_, Sep 15 1998 %E A046517 Offset corrected by _Robert Israel_, Feb 12 2019