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%I #25 Mar 07 2022 02:13:26
%S 25,26,27,28,29,34,35,36,37,38,43,44,45,46,48,52,53,54,56,58,62,63,64,
%T 65,67,72,73,76,82,83,84,85,92,99,125,126,127,128,129,134,135,136,137,
%U 138,143,144,145,146,148,152,153,154,156,158,162,163,164,165,167,172
%N Numbers with multiplicative persistence value 2.
%H Daniel Mondot, <a href="/A046511/b046511.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..3000 from Vincenzo Librandi)
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/MultiplicativePersistence.html">Multiplicative Persistence</a>
%e 129 -> [ 18 ] -> [ 8 ] = one digit in two steps.
%t mpQ[n_]:=Length[NestWhileList[Times@@IntegerDigits[#]&,n,#>9&]]==3; Select[Range[200], mpQ] (* _Harvey P. Dale_, Apr 12 2014 *)
%o (Python)
%o from math import prod
%o def pd(n): return prod(map(int, str(n)))
%o def ok(n): return n > 9 and (p := pd(n)) > 9 and pd(p) < 10
%o print([k for k in range(173) if ok(k)]) # _Michael S. Branicky_, Jan 16 2022
%Y Cf. A003001, A014120, A046502.
%K nonn,base
%O 1,1
%A _Patrick De Geest_, Sep 15 1998
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