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Duplicate of A080773.
0

%I #8 Mar 31 2012 13:21:04

%S 1,2,2,2,3,3,3,4,3,3,4,3,4,4,4,2,5,3,4,5,4,4,5,4,4,6,5,4,5,5,5,5,3,5,

%T 6,3,4,5,5,3,6,4,5,6,5,5,6,6,5,4,5,4,7,5,6,5,5,5,6,5,6,7,6,5,6,3,4,6,

%U 6,4,7,3,4,6,5,6,6,5,6,8,4,4,7,4,5,6,6,4,7,6,6,7,6,5,7,3,7,7,6,4,5,5,6,7,5

%N Duplicate of A080773.

%F If p_1*p_2*p_3* ... *p_m=n is the unique prime factorization of n, then a(n)=sum{1<=k<=m, ds_2(p_k)}, where ds_2 is the digital sum base 2.

%e a(6)=3, since 6=2*3 and so a(6)=ds_2(2)+ds_2(3)=1+2.

%K dead

%O 2,2

%A _Hieronymus Fischer_, Nov 11 2007