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A046518 Numbers with multiplicative persistence value 9.

%I A046518 #24 Feb 16 2025 08:32:39
%S A046518 26888999,26889899,26889989,26889998,26898899,26898989,26898998,
%T A046518 26899889,26899898,26899988,26988899,26988989,26988998,26989889,
%U A046518 26989898,26989988,26998889,26998898,26998988,26999888,28688999
%N A046518 Numbers with multiplicative persistence value 9.
%H A046518 Daniel Mondot, <a href="/A046518/b046518.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..1000 from Robert Israel, terms 1001..7448 from David A. Corneth)
%H A046518 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MultiplicativePersistence.html">Multiplicative Persistence</a>
%e A046518 26888999 -> [ 4478976 ][ 338688 ][ 27648 ][ 2688 ][ 768 ][ 336 ][ 54 ][ 20 ][ 0 ] -> one digit in nine steps.
%p A046518 mp:= proc(n) option remember;
%p A046518     if n <= 9 then return 0 fi;
%p A046518     1+procname(convert(convert(n,base,10),`*`))
%p A046518 end proc:
%p A046518 filter:= proc(n)
%p A046518   evalb(mp(convert(convert(n,base,10),`*`))=8)
%p A046518 end proc:
%p A046518 select(filter, [$26111111..29999999]); # _Robert Israel_, Feb 12 2019
%Y A046518 Cf. A003001, A014120, A046509.
%K A046518 nonn,easy,base
%O A046518 1,1
%A A046518 _Patrick De Geest_, Sep 15 1998
%E A046518 Offset corrected by _Robert Israel_, Feb 12 2019