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%I #21 Apr 23 2022 12:36:48
%S 679,688,697,796,868,886,976,1679,1688,1769,1796,1868,1886,1967,1976,
%T 2379,2388,2397,2468,2486,2648,2684,2688,2739,2793,2838,2846,2864,
%U 2868,2883,2886,2937,2973,3279,3288,3297,3367,3376,3448,3484,3488,3729,3736,3763
%N Composite numbers whose multiplicative persistence is 5.
%C Complement of A046505 with respect to A046514.
%H Harvey P. Dale, <a href="/A199995/b199995.txt">Table of n, a(n) for n = 1..1000</a>
%e 679 -> [ 378 ][ 168 ][ 48 ][ 32 ][ 6 ] -> one digit in five steps.
%t persistence[n_] := Module[{cnt = 0, k = n}, While[k > 9, cnt++; k = Times @@ IntegerDigits[k]]; cnt]; Select[Range[4000], !PrimeQ[#] && persistence[#] == 5 &] (* _T. D. Noe_, Nov 23 2011 *)
%t mp5Q[n_]:=CompositeQ[n]&&Length[NestWhileList[ Times@@IntegerDigits[ #]&,n,#>9&]] == 6; Select[Range[4000],mp5Q] (* _Harvey P. Dale_, Apr 23 2022 *)
%Y Cf. A046505 (primes whose multiplicative persistence is 5).
%K nonn,base
%O 1,1
%A _Jaroslav Krizek_, Nov 13 2011
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