%I A061903
%S A061903 0,1,4,1,3,3,1,2,2,1,1,4,1,2,2,1,2,3,1,2,4,1,2,2,2,2,3,2,3,2,1,2,3,2,2,
%T A061903 2,2,3,2,1,3,2,2,3,3,1,2,2,1,3,3,1,2,3,2,2,2,2,2,2,1,2,3,3,3,2,2,3,2,2,
%U A061903 2,2,2,3,3,2,3,3,2,2,2,2,3,3,2,2,3,3,3,3,1,3,3,3,3,2,2,3,3,2,1,4,1,2,2
%N A061903 Number of distinct elements of the iterative cycle: n -> sum of digits 
               of n^2.
%C A061903 It seems that any such iterative cycle can contain at most 4 distinct 
               elements.
%e A061903 a(2) = 4 since 2 -> 4 -> 1+6 = 7 -> 4+9 = 13 -> 1+6+9 = 16 -> 2+5+6 = 
               13, thus {4,7,13,16} are the distinct elements of the iterative cycle 
               of 2. a(6) = 1 since 6 -> 3+6 = 9 -> 8+1 = 9 thus 9 is the only element 
               in the iterative cycle of 3.
%Y A061903 Cf. A007953, A004159, A061904 - A061910.
%Y A061903 Sequence in context: A021246 A019633 A067277 this_sequence A084118 A046071 
               A078147
%Y A061903 Adjacent sequences: A061900 A061901 A061902 this_sequence A061904 A061905 
               A061906
%K A061903 nonn,base
%O A061903 0,3
%A A061903 Asher Auel (asher.auel(AT)reed.edu), May 17 2001