%I A014553
%S A014553 1,4,5,6,7,7,8,9,9,10,10,10,10,10,11,11,11,11,11,11,11,11,11,11,11,11,
%T A014553 11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,
%U A014553 11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11
%N A014553 Maximal multiplicative persistence (or length) of any n-digit number.
%C A014553 The "persistence" or "length" of an N-digit decimal number is the number 
               of times one must iteratively form the product of its digits until 
               one obtains a one-digit product (For another definition see A003001.)
%C A014553 For all other n<2530, a[n]=11 because sequence is non-decreasing and 
               a number with multiplicative persistence 12 must have more than 2530 
               digits. - Sascha Kurz (sascha.kurz(AT)uni-bayreuth.de), Mar 24 2002
%D A014553 Gottlieb, A. J. Problems 28-29 in ``Bridge, Group Theory and a Jigsaw 
               Puzzle.'' Techn. Rev. 72, unpaginated, Dec. 1969.
%D A014553 Gottlieb, A. J. Problem 29 in ``Integral Solutions, Ladders and Pentagons.'' 
               Techn. Rev. 72, unpaginated, Apr. 1970.
%H A014553 Beeler, M., Gosper, R. W. and Schroeppel, R., <a href="http://www.inwap.com/
               pdp10/hbaker/hakmem/number.html#item56">HAKMEM, ITEM 56</a>
%H A014553 N. J. A. Sloane, <a href="http://www.research.att.com/~njas/doc/persistence.html">
               The persistence of a number</a>, J. Recreational Math., 6 (1973), 
               97-98.
%H A014553 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               MultiplicativePersistence.html">Link to a section of The World of 
               Mathematics.</a>
%e A014553 168889 is not in A003001 because a(6) = a(5) = 7
%Y A014553 Cf. A003001, A031346, A035927.
%Y A014553 Sequence in context: A114546 A067471 A102691 this_sequence A121855 A090925 
               A143836
%Y A014553 Adjacent sequences: A014550 A014551 A014552 this_sequence A014554 A014555 
               A014556
%K A014553 nonn,easy,base
%O A014553 1,2
%A A014553 Eric Weisstein (eric(AT)weisstein.com)
%E A014553 Corrected by N. J. A. Sloane (njas(AT)research.att.com) 11/95.
%E A014553 More terms from John W. Layman (layman(AT)math.vt.edu), Mar 19 2002