|
%I #20 Mar 13 2022 13:37:11
%S 2678789,2687879,2687897,2688797,2688977,2689877,2697887,2768789,
%T 2768897,2769887,2778689,2786789,2787689,2788769,2798687,2798867,
%U 2868779,2868977,2876789,2876879,2878679,2878697,2878769,2879687
%N Primes with multiplicative persistence value 8.
%H Daniel Mondot, <a href="/A046508/b046508.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..9001 from Harvey P. Dale)
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/MultiplicativePersistence.html">Multiplicative Persistence</a>
%e 2678789 -> [ 338688 ][ 27648 ][ 2688 ][ 768 ][ 336 ][ 54 ][ 20 ][ 0 ] -> one digit in eight steps.
%t mp8Q[n_]:=Length[NestWhileList[Times@@IntegerDigits[#]&,n,#>9&]]==9; Select[ Prime[ Range[210000]],mp8Q] (* _Harvey P. Dale_, Mar 30 2019 *)
%Y Intersection of A000040 and A046517.
%Y Cf. A046500.
%K nonn,base
%O 1,1
%A _Patrick De Geest_, Sep 15 1998
|
