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%I #13 Oct 13 2019 23:24:35
%S 6788,6878,6887,7688,7868,7886,8678,8687,8768,8786,8867,8876,16788,
%T 16878,16887,17688,17868,17886,18678,18687,18768,18786,18867,18876,
%U 23788,23878,23887,24678,24687,24768,24786,24867,24876,26478,26487
%N Numbers with multiplicative persistence value 6.
%H Robert Israel, <a href="/A046515/b046515.txt">Table of n, a(n) for n = 1..10000</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/MultiplicativePersistence.html">Multiplicative Persistence</a>
%e 6788 -> [ 2688 ][ 768 ][ 336 ][ 54 ][ 20 ][ 0 ] -> one digit in six steps.
%p mp:= proc(n) option remember;
%p if n <= 9 then return 0 fi;
%p 1+procname(convert(convert(n,base,10),`*`))
%p end proc:
%p select(mp=6, [$1..30000]); # _Robert Israel_, Feb 12 2019
%Y Cf. A003001, A014120, A046506.
%K nonn,base
%O 1,1
%A _Patrick De Geest_, Sep 15 1998
%E Offset corrected by _Robert Israel_, Feb 12 2019
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