%I A102442
%S A102442 0,0,0,0,1,0,1,0,0,1,2,0,2,1,1,0,2,0,2,1,1,2,3,0,1,2,0,1,3,1,3,0,2,2,1,
%T A102442 0,2,2,2,1,3,1,3,2,1,3,4,0,1,1,2,2,3,0,2,1,2,3,4,1,4,3,1,0,2,2,3,2,3,1,
%U A102442 4,0,4,2,1,2,2,2,3,1,0,3,4,1,2,3,3,2,4,1,2,3,3,4,2,0,3,1,2,1,3,2,3,2,1
%N A102442 Number of iterations needed to transform n by A102440 into a 3-smooth 
               number.
%C A102442 a(n) = 0 iff n is 3-smooth (A003586);
%C A102442 a(A102444(n))=n and a(m)<n for m<a(A102444(n)).
%e A102442 A102440(A102440(A102440(41)))=24 and A102440(24)=24:
%e A102442 41 -> 3*13 -> 3*[13->2*5]=2*3*5 -> 2*3*[5->2*2]=3*2^3=24,
%e A102442 therefore a(41)=3, A102443(41)=24.
%Y A102442 Sequence in context: A060950 A039976 A133701 this_sequence A091182 A001822 
               A112553
%Y A102442 Adjacent sequences: A102439 A102440 A102441 this_sequence A102443 A102444 
               A102445
%K A102442 nonn
%O A102442 1,11
%A A102442 Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jan 09 2005