A046514 - OEIS

%I #13 Oct 13 2019 23:24:25

%S 679,688,697,769,796,868,886,967,976,1679,1688,1697,1769,1796,1868,

%T 1886,1967,1976,2379,2388,2397,2468,2486,2648,2684,2688,2739,2777,

%U 2793,2838,2846,2864,2868,2883,2886,2937,2973,3279,3288,3297,3367,3376,3448

%N Numbers with multiplicative persistence value 5.

%H Robert Israel, <a href="/A046514/b046514.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 2777 -> [ 686 ][ 288 ][ 128 ][ 16 ][ 6 ] -> one digit in five 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=5, [$1..4000]); # _Robert Israel_, Feb 12 2019

%Y Cf. A003001, A014120, A046505.

%K nonn,base

%O 1,1

%A _Patrick De Geest_, Sep 15 1998

%E Offset corrected by _Robert Israel_, Feb 12 2019